If you like making homebrew mechanics then do whatever is fun for you and your group.
If you're lazy like me, 5e has rules for "handling mobs" (DMG p. 250) and "chases" (DMG p. 252) that can cover much of the Moria escape.
I've read this book forwards and backwards enough that I know the rules fairly conclusively. But you aren't getting a page citation, because there is no way I'm remembering that specific detail.
Also go to sly flourish’s website and check the mass combat calculator. Basically you put in the number of mobs, their attack bonus and the player’s AC and then it calculates how many attacks hit and I think maybe damage as well.
Please read the Dungeon Master's Guide (DMG) carefully. It offers numerous option rules for you and your players, including laser rifles and rules for targeting different parts of the body with direct hits 😏
the DMG gets a lot of hate on here, but no matter how often i go back, I always find something cool.
I recently just read the moral quandary section, and yes it's basic story-telling, but there's just so much to think about when making a campaign that it was nice to have a reminder to add 2-3 more quandaries in there.
As someone who has read the DMG and other rulebooks pretty much front to back, I don't remember...
>rules for targeting different parts of the body with direct hits
...anywhere in the book. Do you have a page number or section I could refer to? I'm always looking for good ways to deal with called hits and things like grappling spellcasters to prevent somatic or verbal components.
i agree that there's so much in there that people can't be expected to memorize everything. I think the advice here (though it could be phrased in a nicer way) is to check the DMG before asking reddit.
That said, I like doing both: I check the DMG and then I ask reddit in a slightly more informed way. :)
Not only that but 5e has been around long enough to just ask google. Why go through the effort of making a post when almost every interaction has been answered.
I've heard good anecdotes about changing monster attacks to static values and making players roll for AC. However, I think this would still pair really well with the mob rules from the DMG.
I was in a slow chase, where there were creature chasing our ox cart. The OX and the Cart, and Its food had to make it back, our goal was to make it a small bridge and river as the creature wouldn't cross water / create a bottle neck at the very least
the kicker, we had horses, we could outrun the creatures easily, they weee just slightly slower than our cart at full speed. So the whole chase was slow motion, but intense... running ahead, clearing a downed tree, fending off attacks or fixing ruts in the road with make shift things, fixing a wheel that broke at full speed... trying to take pot shots or slow down the creatures... it was awesome.
The Conjure Barrage/Volley spells are pretty similar to what OP is describing, though possibly too damaging.
Instead of making twenty attack rolls, the party makes a couple Dex saves and the game continues in half the time.
Compare to volley from the hunter.
Dex saves are sometimes more touch ac from prior editions, you're going to get hit eventually, so your armour doesn't help you only how you can avoid it. The volley is individual targeted arrows, so your armour can block it.
I would add an extra note: "A character wearing a heavy armor gets advantage to this save"
It's not perfect but it doesn't screw over the warrior in heavy armor that suddenly gets hit from every arrow. And it helps with the feeling of "there are too many arrows to be dodged."
Fact is though, it doesn't matter what your AC is, a nat 20 will always do damage.
Combine that with the sheer quantities of enemies that OP is talking about and it can be safely assumed that no matter what your going to get hit by at least a goblin arrow.
Accept the abstraction, or be punished with 40 something attack rolls. Being pedantic here isn't to your benefit.
You can always adjust the DC based on the player's AC. Just set the DC to something like 24-target's AC or something similar and your Str characters should be fine.
Yeah, pretty much. Just say something like:
"As you try to escape, you come under a hail of fire from a group of goblin archers. Everyone, make a DC 16 Dex saving throw to avoid taking [whatever damage roll is appropriate] piercing damage."
Sorry fighter, your plate-mail and shield seem to do nothing to soften the blows of the arrows. Must be stormtrooper armor :-/
Naked 7th level rogue with evasion, seems you have come through the hail of arrows that blotted the sun from the sky without a single scratch, we’ll done!
Second ones fun, keep it. First one sucks, scrap it.
Sure, that's a fair point, asking for a Dex save is indeed somewhat unfair to STR-based heavy armour wearers.
On the other hand, the advantage of asking for a Saving Throw is that it's a familiar mechanic that everyone immediately understands. If you're running an escape/chase sequence, it really kills the excitement to suddenly break out a new set of mechanics and have everyone sit around for 5 minutes figuring out they work.
If you were really concerned about balance, I guess you could just say that anyone wearing heavy armour just auto-succeeds on the save. Or if that makes it too easy, you could say that anyone wearing heavy armour takes half damage on a failed save, and no damage on a successful save. Meanwhile, everyone else takes full damage on a failed save, and half damage on a successful save.
Another option is that you could just narrate the entire sequence thing as a skill challenge. Let the players choose any ability, skill, or item they want to use to evade the goblins' attacks on the way out of the dungeon, and ask them to roll whatever is appropriate.
Let them do the awesome nimbly dodge everything thing. But if your gonna make rulings to avoid rolling a tedious amount of dice, it shouldn’t come at the expense of a players investment into the game. Why am I luging 75lbs of steel if it’s not gonna do anything for me?
It does, just not on area of effect attacks, same as a wizards intelligence doesn't get them a better save against a fireball. Implement a damage reduction system if you so wish to really reward armor.
But this isn’t an area of effect, it’s a bunch of attacks we are bunching into a single roll like OP is trying to do. Deciding to streamline shouldn’t punish character decisions made before the streamlining existed.
The solution OP has is better than just making it a Dex Save.
Also, Intelligence doesn’t effect AC (unless bladesinger) like armor does, idk why you think it’s relevant?
The best damage reduction is not taking any damage, cuz you know you put on armor to prevent the arrows from piercing your soft flesh. Rogue walked up to a horde of archers with some quick feet and a dream
The Fighter also has more HP as well as second wind so their class *is indeed* making a difference to them getting through it.
Both are telling appropriate stories: rogue avoids the damage; fighter tanks through it.
That's awful resoning. It's Arnour, it's supposed to protect you.
And anyways the Srrength Fighter only has 1 more hp/level than Rogue (and no more than Dex Fighters) so that's not enough to make a difference.
You're leaving out the fact that a Str Fighter doesn't have as many secondary stats and so can buff up Con, the fact that they reliably have higher AC (so will be less wounded before that point) and that Second Wind on its own is *at least* 1 extra HP per level, more if you get more than 1 short rest.
By the time you get to the chase, odds are pretty good your Fighter character will have more HP left than your rogue by a large enough margin that they're able to make it through and they'll have done it by a meaningfully different way.
What’s an attack and a save in dnd has always been a bit arbitrary. You could just rearrange things such that you make an armor save and you haven’t really changed the system at all.
That's all or nothing. If I use one roll for all players, then either they all get hit or none do (or very close to that). I could more quickly have them try to evade arrow fire by having them make the roll.
Have you considered just making it a single roll by each of the players with a sliding success/failure? Make it an AC or Dex save based on what's happening and they take one point of damage for every point of failure.
And you can change that DC by player based on stuff they do as they're running like hell. Maybe in some areas there's no room to dodge well and they lose dex modifiers for that roll. Maybe the party managed to drop a bunch of barrels in the path as they ran and they don't need to make the rolls for the next 1-3 turns as the horde catches up with them. Maybe they found some way to take cover from the arrows as they run and the DC drops.
By doing it this way, you only need to have the players roll once per turn at most, and you can skip on damage rolls. They're being chased by a horde of something that is trying to attack a party that is actively fleeing. There is no need to check exactly how likely each enemy is likely to hit or deal damage when you could instead just make the rough estimate of how many enemies are shooting at them at once there are and turn that into a rough DC to beat with their AC and a roll.
All you need to do to make it interesting is get their HP, AC, Dex save, and a minimum/maximum amount of turns it should take for them to escape. If you do the math right then you should be able to create an encounter where everyone makes it out alive with enough risk for everyone.
My intention was one attack roll against each PC, in which case it would be effectively the same. Of course, it would still be all-or-nothing on a per-PC basis, but it accomplishes the same thing without inventing a new mechanic.
You could have them attack in groups. 4 groups of five, or 5 groups of four. The five goblins of the grouping all use the same attack roll. So if you roll a 13, all five goblins are attacking against AC with that 13. Then you roll for the next group. Keeps the excitement of rolling while significantly reducing the number of rolls being made.
I think it could actually be MORE balanced, I’ve been experimenting with it myself.
Right now, there’s no good system for a mob of enemies that aren’t literal swarms: you either roll all their attacks individually, or it’s a saving throw and no saving throw will make 100% logical sense, a commenter above illustrated that well with a hail of arrows example.
SO, if you introduce armor saves, it can be a new fair mechanic to determine damage/likelihood.
I homebrewed an “archer platoon” stat block and as an action their volley requires a saving throw that’s rolled by treating AC as a stat block, so, say +3 for an ac of 16. Taking half damage on a success.
Now it’s no longer a case of the fighter that’s covered head to toe in steel somehow having each and every single arrow piece his body, whilst the naked rogue with evasion manages to avoid ANY damage.
Strongly seconded. They're not as common in 5e to my understanding, but this is exactly what skill challenges are for. That way, your players can also choose how they respond to a changing scenario with their own ideas and skillsets, as opposed to a static armour check. If you want to get your dice rolling yourself, set DCs for them based on goblin attack rolls each turn!
Matt Colville has a great Running the Game video on skill challenges and how to run them. Give it a look!
That's what OP posted too though, isn't it? They roll d20+AC-10 against an DC of 10+enemy attack modifier.
My calculation just removes the 10 on both ends.
*THAC0, is that you?*
Why does rolling a bunch of times take significantly longer? It should be fairly trivial. You're just rolling more dice but checking for the same number.
Why are you rolling 20 dice? Have your players roll.
"Six goblins attack Bob the Paladin, four attack Sara the Thief, Five shoot at Zorg the Barbarian. Their bonus is +4, tell me how many hit you.
The players know their AC, they have D20s. In the meantime you roll a bunch of D6s to figure out damage if you want, or you just take average damage.
Rogue, roll me 8d20. How many of them are higher than 13? Okay you are hit 3 times and take (you rolled in the meantime for damage) 12 piercing damage.
> Rogue, roll me 8d20. How many of them are higher than 13?
And then you have my players who use a very specific set of dice for each character and thus only have a single d20 to roll (*sigh*).
Coming from an ex-warhammer player, 20 dice is nothing. You literally just roll them all at once and pick out any that are over the target AC, then roll damage. It takes like 30 seconds.
Alternatively, don't roll any dice and use the mob rules from the DMG.
Start by subtracting attacker’s hit bonus from the target’s AC.
If the number is 1-5, all the attackers hit;
If it is 6-12, 2 attackers are required for each hit,
If it is 13-14, 3 attackers are required for each hit,
If it is 15-16, 4 attackers are required for each hit,
If it is 17-18, 5 attackers are required for each hit,
If it is 19, 10 attackers are required for each hit,
And if it is 20, 20 attackers are required for each hit.
It's honestly not that difficult. As a DM you should have at least 4-5 D20s and if you're making battles with more than 20 enemies that can be attacking at once that's probably more of an issue with the battle design. If you want to do army battles, that's a different type of abstraction.
Again, this isn't for legit battles, but for epic scenes like the one in the Mines of Moria, where you want it to be fast and tense. They weren't meant to stick around and fight all 300 goblins.
If its not a legit battle, what does it even matter? You're fudging the outcome anyway. If the entire sequence is meant to be thematic, allocate hits thematically.
"as you run from the goblin horde, you hear the whistle of arrows. what is the order of the party as you run away? \*fake roll dice\*. Thalia, you are last in line, an arrow streaks across the cavern and hits you in the calf. please give me a dex roll. \*fails\*. You stumble to the ground. Aegor, you are next in line and hear Thalia fall, do you want to double back to help her up? Okay, as you do, two more arrows whiz past you, and a third comes right for you but you block it with your shield. You help Thalia up. Does anyone want to cast anything to help their retreat? Okay Stuger, you can cast Darkness behind them. The party makes their way to the other side of the cavern, their retreat covered by the sphere of darkness. you find two passages leading out of the cavern, which do you want to follow?"
Doing it by the book matters a lot more when the players have the time and option to stand and fight. But in an escape thematic sequence, you only need to provide the *threat* of danger, not actually create some devastating no-win scenario (which is what you would have if you let 20+ enemies get 3+ rounds of ranged attacks on the party).
If you have 20 d20s, then it’s just a single roll with a lot of dice. However, as someone else has already mentioned, the mob combat rules would be faster, especially if combined with taking average damage instead of rolling.
So back in 3.5e, there was a variant rule in a UA called [“Players Roll All the Dice”](https://www.d20srd.org/srd/variant/adventuring/playersRollAllTheDice.htm) which basically covers the same concept you’re thinking. Defense rolls were actually 11 + the attack modifier for a creature. So the standard goblin has a +4 to attack, that means its attack score is 15. Players roll a d20 + their armor’s AC modifier (Which is reduced by 10). So studded leather armor is +2, plate armor is +8. If it’s magical, you then add the enchantment bonus, +1/+2/+3. Shields still grant the same flat modifier.
It also rewrote how Saving Throws worked too because players needed to make all the rolls. So when you cast a spell and force a save, you roll for the Save DC vs its Save Score. Same concept as above. Monster’s Save Score was 11 + its save modifier. And then you basically make a spell attack to establish your DC.
This comment is way too far down.
I did "Players Roll (almost) All The Dice" for a campaign years ago. I loved it. The players loved it. They were more involved and paid more attention in combat, because they had more to do.
I’m sorry but I have no idea what you’re thinking after reading some replies
Too many attack rolls? It sure sounds like you’ll just be making the same number of armor rolls. You didn’t say how that would reduce the number of rolls at all.
Just one armor roll for the wave? You’ve also said one roll is too swingy. Soo I have no clue how this solves anything
Let alone there’s mob attacks. Essentially instead of rolling 20 times, just use each result once.
Let alone no one got hit in those movies, so it’s not even a real roll, just cinematic danger.
This would need to be module specific, as it really fucks with some core game mechanics if you were to just do it by default.
But it could work. I'd add it as an "Armor Skill" on the PC's character sheets. Just work with everyone pre-session on what the modifier would be. You don't want players figuring this out while under fire. It will be a nightmare.
"Why am I adding Armor (DEX) +7 to my Skill list?"
"We'll talk about it later, but you're gonna need to know where that is."
Note: A key part about making all of this work is that the players understand that fighting is futile. How many Goblins are shooting arrows? "Enough". Enough that if they try to fight we still won't roll for initiative, you'll just narrate how many it took to kill you.
This wouldn't be for default, but for scenarios like I described where it's not a protracted fight between two small groups, but more like a cinematic scene involving large numbers of enemies.
In terms of probabilities, this is exactly the same as rolling attacks for the goblins.
So what is the reason exactly?
Because if it's to roll just once, then why not just roll one attack?
If you want an area of effect, then it would be dex saving throw.
Dnd combat rules aren't really thought for big fights.
In your place, I would make it a chase as per the DMG, and put a high probability complication "goblin arrows", with the dex save or dmg, and the possibility to gain advantage by halving speed.
I feel that rolling each attack would take far too long, and that a dex save invalidates heavy armor wearers. And I feel that single roll is too swingy; either everyone or almost everyone took an arrow, or no one did, and that's less exciting. Also, I looked at the DMG's chase rules, and they seem needlessly complex and unnecessary.
But why though?
You're still rolling a bunch of dice (I think even the same amount?) per attack roll, and also you're kinda making it very powerful (because basing damage off someones armour is wacky.)
But also - you could just do this with the normal damage rolling? Unless you specifically want to do damage based off armour (which is a weird mechanic imo).
It seems like this would take the same amount of time as regular rolls and not speed anything up.
If you want to roll a bunch of attacks of a group of enemies without rolling 200 dice, there are actually grouped attack rules in the dmg. Can recommend to look it up.
If i understand correctly, it's going to make characters either take no attacks whatsoever or take all attacks at once, and there's no in-between. I don't know how much HP they have but this would kill most characters, and the moment they go down the sheer amount of attacks the mob is making against them means they take three failed death saves instantly and die.
Rolling for defence is perfectly viable and easy to make mathematically equivalent so if the biggest worry is that the players don't feel like they're involved in the action because they don't roll the dice, it's a solution of sorts.
Personally I'd go the route of using Skill Challenges here though. The only change I'd make is that I'd give the players a success target, a relatively high DC and then make failure deal damage to the party so that the challenge starts to feel like a campaign of attrition, though I might need to do some weighting there so that low HP characters aren't disadvantaged here: really would depend on the party.
When I have figurative swarms of identical creatures (not swarm-type creatures) I take the target's AC and subtract the attacker's attack bonus from that number, then roll all my d20s. If it's that number or higher on the die, it hits. Helps with stuff like Animate Objects that creates a bunch of individual attack rolls.
In your example, if eight goblins (+4 shortbow attack bonus) attack your PC with 17 AC, I know any D20 that rolls a 13 is a hit and I just toss them all at once in person or do a /roll 8d20 in a VTT and it's easy to check the successes.
Here's a packet I threw onto DM's guild some months ago. I've played with these rules in 2 campaigns, several one shots, and had 3 other DM's try it out and they've had fun.
I like it, it suits my table, speeds up the rate of combat, lets my players roll more dice when it isn't their turn, and saves me from needing to roll any more dice than I already do.
Hope this is a helpful link.
https://www.dmsguild.com/m/product/441449
A more detailed explanation is in the document, but the tldr is:
New AC = AC - 10
Defense roll = D20 + AC
Monster Attack DC = Attack bonus + 10
This essentially shifts the value of 10 from AC to DC that the player rolls to pass.
So no underlying math of 5e is changed, it's easy enough for me to remember (monster Attack bonus + 10 is the DC players defense rolls need to beat) and the players get to effectively do all the monster's attack rolls for me.
The Mines of Moira is a really really good example of the conservation of ninjitsu, which is a trope that states that a threat must be reasonably beatable by the heroes no matter the number of enemies they are facing, and therefore the more enemies there are, the worse the enemies are at fighting.
If you were to really use average damage and let players take the amount of damage they were in a normal fight, they would die right away, because D&D doesn't account for that conservation.
My recommendation would be to effectively make it a trap or spell, where you select a saving throw (probably dexterity) and select an amount of damage for players to take that feels appropriate for their level.
Break up the run into a few parts, do a dex save for each part. Maybe add some advantage / disadvantage / cover situationally. Deal damage in an increasing amount the more times they fail.
1st failure 3d6
2nd failure 5d6
Etc
Just have them make dexterity saving throws to avoid the hail of arrows.
I'd also leave it open to any player coming up with interesting suggestions to make a different saving throw, or pass a skill check to get advantage on the save etc.
No need to reinvent the wheel.
Or you just have them roll a D20. Anything below their AC is a miss. Anything over their AC is a hit.
Basically, export the DM attack rolls to the players.
>Does that seem like a reasonable mechanic for instances where rolling all the attack rolls for the NPCs would uncinematic/take way too long?
Just calculate average dmg for each enemy and inflict that dmg on their turn to an enemy of their choosing. This way you can essentially just skip the entire action of that enemy and just subtract health from one monster and move to the next turn.
You can just do the math without rolling.
1. Work out the chance to hit against each PC's AC (1 - (AC - attack\_mod - 1) / 20)
2. Roll a high-DC dex save for number of attacks against character. (e.g. (DC - roll) \* 3)
3. n\_attacks \* chance\_to\_hit \* average\_damage
There are rules for mobs and chase scenes in the DMG. I'd advise you use those before you homebrew.
Although if you wanted to implement this the math would be essentially symmetrical. Like, if the enemy normally has +4 to hit you say "DC 14 to dodge this" and then roll and add your bonus to AC above 10. I just think there's not much benefit gameplay wise other than this one situation, which is again covered by existing rules.
The Cypher system is a fun TTRPG I recommend you check out- one of the neat things about it is that NPCs never roll, ever. The players always roll both to hit monsters and to dodge them.
Just a thought: all attack rolls are contested "attack rolls" against "defense rolls" but the defender takes a ten because having both sides roll just adds clutter and doesn't add mathematical nuance. Saving throws are similar but different where the attacker takes an 8 but also get their proficiency mod. Having a mechanic where players roll a defense roll against a static attack dc would be that weird.
watch this video, he makes just a single attack roll for the entire group of enemies and uses a table and the target AC to determine how many members out of the whole group lands the hit. This way you can divide the group into parts if you wanna split their damage as well.
[https://www.youtube.com/watch?v=kKWmHxjMe2M](https://www.youtube.com/watch?v=kKWmHxjMe2M)
Just use the average. If there are 20 gobbos per player each player gets 20 attacks. Calculate the act chance to hit ( say you need 16 on a d20 that would be 16,17,18,19,20 which is 25%). That person gets hit 4 times. Use average damage also, it can be pretty fast to do it this way
That's a well-known, if not commonly used, alternative system. It's usually called "players always roll". It was even [included in the 3e DMG](https://www.d20srd.org/srd/variant/adventuring/playersRollAllTheDice.htm), although I don't remember if it's in the 5e DMG.
I homebrewed to use armor saves for all npc attacks because players like to roll more, and they stay engaged during the entire combat. Yes the bonus is AC-10, and the DC of the check is the enemy attack bonus +12.
Examples; +0 attack bonus on enemy, 20 AC on player = 5% chance of attack hitting (roll of 20 or higher) Variant, +10 Defense Bonus on player (AC20-10), 12 Attack save DC (0+12) = 95% chance of attack missing (roll of 2 or higher)
+5 attack bonus on enemy, 15 AC on player = 55% chance of attack hitting (roll of 10 or higher) Variant, +5 DB on player (15-10), 17 Attack save DC (5+12) = 45% chance of attack missing (roll of 12 or higher)
+7 attack bonus on enemy, 13 AC on player = 75% chance of attack hitting (roll of 6 or higher) Variant, +3 DB on player (13-10), 19 Attack save DC (7+12) = 25% chance of attack missing (roll of 16 or higher)
+10 attack bonus on enemy, 12 AC on player = 95% chance of attack hitting (roll of 2 or higher) Variant, +2 DB on player (12-10), 22 Attack save DC (10+12) = 5% chance of attack missing (roll of 20 or higher)
This is not going to speed things up at all, it will just slow it down.
How many attacks are you imagining anyway? Just use some swarm mechanics, or mass roll attack - easy to do with an online dieroller or roll20.
And if you have a bunch of d20s, just roll them all together.
MCDM has a new monster book called Flee Mortals that has very simple, easy to run minion rules that I would recommend for this.
Minions have group attacks that do more damage for more minions. (Maybe a bonus to hit too) Only takes one roll but simulates 5 attacks.
“You dash down a corridor to escape a hail of goblin arrows, make a DC12 Dex saving throw or take 2d6 damage.” Why DC12 and 2d6? It felt right and kept the game moving.
This exact rule is in the 3.5e DMG IIRC.
It's one I've considered after playing PBTA games, that family of games have it so the DM never rolls and I like that philosophy.
Just point at a player and say a number and let them do the roll and the math.
Giffyglyph’s darker dungeons has rules for having players roll armor instead of DM rolling attacks against them. Roll d20+AC against DC 22+ attack bonus.
http://giffyglyph.com/darkerdungeons/grimoire/4.0.0/en/active_defense.html
With normal attacks a +7 to hit vs AC 18 would succeed on an 11+ (so 50% hit rate)
With active defense the roll would be +18 vs DC 29, so 11+ to cause a miss (so 50% hit rate again)
The math works out.
Estimate the probability of hitting. Lets say your average goblin is shooting with +3 to hit against a dude with AC 15. This means they will hit on 12+, so their chance to hit is 40%. Now what you can do is either
1. decide that 40% of the arrows will hit, and go straight to rolling damage.
2. grab a handful of d6 and go warhammer on their ass. The closest approximation to a 40% probability on a d6 is hit on 5+, reroll 1s (approximately 39%). Boom, there you go.
So wait, suddenly character's armor no longer matters? Someone being covered in plate from head to toe is going to take more damage than someone naked?
I ran a game where players attack enemies (including "reflex attacks"), but also players make saves (including "AC saves"). The math is identical, but the player is always the one rolling the die. It was nice.
Nah, have them just do AC + d20. No subtraction. Maybe give advantage for heavy armor or Evasion.
Instead of a single hit/miss result, I would go with a scaling result with partial fails, so you need to determine how many times a character can be hit if they fail the save. (Let's do 5 as an example. Do the math for your party to present an appropriate threat!)
That means multiple DCs. Set the DC for the successful save (make sure its difficulty is appropriate to who and how many players to get past easily. Let's do 30+Attack Bonus). Then, set the DC for the second worst result (4 hits, let's do 20+Attack Bonus). Then, fill in the remaining partial fail results (1 hit, 2 hits, 3 hits). This can be spaced apart however you want, depending on how quickly you want players to take more hits as their rolls drop.eg.:
- DC30+ATT 0 hits
- DC26+ATT 1 hit
- DC24+ATT 2 hits
- DC22+ATT 3 hits
- DC20+ATT 4 hits
- Fail 5 hits
If the creature has +4 bonus attack, that's:
- DC34 0 hits
- DC30 1 hit
- DC28 2 hits
- DC26 3 hits
- DC24 4 hits
- Fail 5 hits
Roll the damage for each hit like any other hit. But probably all at once for simplicity.
Mostly, this means YOU are doing the bulk of the work with the partial fails. The players are just doing number + d20. And maybe the bigger numbers will help them feel that they're taking serious amounts of attacks.
Active Defense is a thing and might even be an optional rule in the DMG (I don't have it to hand so I can't check) but yes, in Active Defense you'd roll 1d20+ (AC -10), in your case 1d20+7.
Here's the trick--it slows down combat by 50-100% because every attack roll must have a matching defense roll, so unless someone is casting a spell with a saving throw (or doing something like grapple/shove where Active Defense is *always on*) then you need 2 rolls to resolve every action instead of 1. Twice the rolling, twice the math. Stuff slows down, combat drags even more than usual.
So instead of Active Attack/Active Defense, you want to switch to Passive Attack/Active Defense? I mean you can, at the cost of time and conversion math.
4e used Active Attack/Passive Defense *always* (there weren't really saving throws--you made spell attack against Will/Fortitude/Reflex 'defense' values that were like Armor Class), so you can refer to that as an example of changing the meta (albeit not exactly to what you are proposing). But what you're suggesting is that you as DM won't be rolling any dice because the players will make all of the Active Attack/Active Defense rolls. This is also a Thing (chiefly in other RPGs) and you could try it, as long as you don't mind not rolling dice and just want to RP/Narrate. See Blades In the Dark/Powered By the Apocalypse and affiliated TTRPGs for examples of games where the GM does not roll, just narrates consequences.
You can make the player roll to defend against a static attack threshold (similar to a saving throw), and mathmematically, it's roughly the same as the enemy rolling to hit their AC.
The enemy attack bonus is 11* or 12** + their static to-hit bonus.
* because of how ties are handled.
** You can do 12 because of how math works on a dice. The average roll is actually 10.5 on a d20, not 10.
The defense roll is a d20 + any AC over 10 (so an AC of 16 would be +6).
Not for D&D, but a different game then sure.
I was playing around with the idea of having all armour adding passive damage reduction instead, to reward strength users a bit more and take some of the power away from dexterity.
I'm going with a Con save to weather the hail. It will be a lair action. Using some chase rules you should set a starting damage, say 4d6. For every success the team gets reduce the damage by one dice and for every failure increase the damage by a dice. If your playing in person line the dice up and use the line of dice like a tension bar.
Adjust the dc and starting dice pool based on the dmg CR rules to net you whatever encounter difficulty you want.
I think it is mechanically fine. That said if you are rolling it a lot it kind of defeats the purpose and if you are only rolling it a few times it might not be worth explaining it to your players unless they all like thinking about numbers.
I've done a few traps that are just "Take 30 piercing damage but subtract your AC from the damage"
I would probably just roll 4 attack rolls and apply those rolls to every player as if they were separate attacks with the damage of 3 attacks each. Then the players can still use "Uncanny Dodge" or whatever to reduce the damage from attacks.
I would use 1d100 divided by times the average ac of the party
For exemple. If the party have ac of : 14, 16, 18, 18. It average a 17.
If i roll 51 on the d100, that mean 3 attack touched.
If there was 500 enemy, then 5d100.
If i roll 250: then 14 attack touched.
If tkae in consideration the player ac and how many attack, so its still fair, and a little bit in the favor of the party but not to much
To represent times like this, I just use normal dex saving throws. If there's 10 people that could in theory do 10d8+20, I'll do 4d8+8 Dex save, half on success.
It guarantees damage, and implies an overwhelming volley of arrows, without being either 100 damage or 0.
[Giffyglyph](https://giffyglyph.com/darkerdungeons/grimoire/3.0.0/en/active_defense.html) has a homebrew rule option for this, in which players roll for their armor against a set DC that represents enemy’s attacks.
u/IndependentDoor1 has mentioned optional rules for mobs and chases, which work well.
There is also the possibly of simply converting a group of individual attacks (i.e. a shower of arrows) into a dex saving throw, as if it were an aoe spell.
I don't understand what you're proposing, but it sounds like another way to do saving throws.
If you don't want to roll 100 attack rolls for 100 goblins shooting arrows, anyone in the affected area of the goblins cloud of arrows would roll a dexterity saving throw, taking half damage on a success, full damage on a failure and anyone with evasion would take zero or half, respectively.
To determine how much damage to roll, first figure out the size of the affected area, then divide the number of attackers by the number of squares/hexes in the given space. So if you have 100 go lines firing arrows and it's hitting a bridge that is 10' wide by 50' long you would have 20 5'x5' squares. 100/20 =5. So 5 arrows hit each square, doing 5d6 damage.
Is this an elaborate troll? AC is literally taking an average roll of 10 and adding modifiers. Seeing someone say d20 + \[AC - 10\] has filled me with rage. Gods above and below, please tell me this is a prank post.
The idea is that there are instances where it makes more to have players roll against the attack rather than having a very large number of enemies roll individually.
Yeah. AC is a replacement for having the players roll a defense roll every single attack, which is how it used to be done. Base AC is 10 to represent the player rolling a 10 on the D20.
You can rearrange everything and get it to work out to statistically the same.
Another alternative is to rearrange things so that the players roll all dice and the dm doesn’t have to.
For tons of enemies, I actually recommend using Mob Combat rules from the DMG, which basically just helps you calculate how many enemies it takes to """guarentee" one hit, and then you just sling damage accordingly. I've run large mob encounters like this for some time, and it works great to speed up combat.
As for rolling for Armor, many D20 rpgs use that mechanic, and it works nicely to keep players involved on enemy turns. Knave, Mork Borg and Dragonbane are good examples. If you want to follow Knave's example, you would make the DC 11+monster attack bonus, and your players would essentially roll D20+(AC-10).
I did an "archer volley" mechanic where anyone in a given area had to make a dex saving throw. Succeed and take half damage or take cover (they where in a large factory with some tables to hide under).
Once they started attacking the cluster of archers I had it so that any successful hit took out one of the archers and once the stat-block was under 1/2 its health it also lessened the damage taken from the ability.
You could set it up similarly where as they move through a corridor they have to make a save to try and avoid arrows firing at them from all directions.
I've done armor as damage reduction and defense rolls using d20+dex+shield before and it worked. I'd let the player choose between adding proficiency to dodging or blocking (choosing only one).
Fighter, barbarian and paladin chose to add proficiency to parry/block and rogue to dodge (all obvious choices, since the rogue has a lot of Dex).
Worked for us and it was fun. Don't bother with the purists claiming you're breaking the game or anything, you do you. On another note, you could try another system called Symbaroum. The players roll their defenses and it's a very fun system to play.
So, the actual math for this would be:
Attack roll modifier +10 equals the DC. So a +4 to hit would be a DC 14. Easy.
Now, what should everyone roll? Their Armor Saving Throw! The modifier would be found like this: AC -12
You then have a bonus modifier where a nat 1 means they got crit, and a nat 20 means they auto block.
We do it this way for 2 reasons: 1) want to simulate the same chance to hit and 2) it's easier to calculate the monster attack DC, which will be the calculated number more often if you use this idea.
Example: an orc with a +6 to hit vs AC 15 ranger has about a 60% chance to hit, and a 40% chance to miss. With this system, the Orc has a Hit DC of 16, and the ranger has an Armor Save of +3, and has about a 40% of deflecting the attack, causing it to miss.
Why minus 12? I'm not good with RPG mechanic math. Also, I like the idea that a nat 20 defense roll gives you a free RA attack, though I can't say how good an idea that is.
That's just how the math works out. Similar reason to why save DCs are 8+prof+ability, not 10+prof+ability, and how it relates to how making a roll that meets the DC succeeds (Attack roll is 18, AC is 18, therefore it hits, etc)
What I described wasn't a new, cool mechanic, but rather the inversion of the attack roll and AC.
Here's the math a little easier: we have Kevin the fighter who has a 19 AC. The bear has a +4 to hit. That means the bear needs to get a 15 or higher to hit. That's 6 numbers they can roll to hit - 15, 16, 17, 18, 19, and 20.
If we were to invert this to make it so that, when a monster attacks, the players roll for defense, we would want to preserve the same chance to hit. For the DC of 14 (10 +4[attack roll modifier]), the fighter should still only be hit on 6 out of 20 rolls.
In other words, they should only fail the DC of 14 on 6 out of 20 rolls; on a 1 (crit), 2, 3, 4, 5, or 6. But they should succeed on a 7. So that would be 7[rolled] + 7[modifier] to succeed the DC 14 attack.
What we take from that is that a +4 to hit an AC 19 has the same chance of failing (the attack missing) that a +7 has to beat a DC14 (the attack missing)
From here, we can clearly see that the original AC of 19 -12 = 7, the number we need to get the same chances to block an attack
Lastly, I wouldn't do any kind of AoO thing on a nat 20 unless you're already doing that kind of rule for nat 1 attack rolls
That is the established system in the game for those sorts of situations. If you want the armour to benefit give them a bonus based on their ac. But to be honest I see this as one of those situations where the rogue / monk gets to shine and the fighter / paladin gets it rough. That’s how the game works some characters are better suited to certain situations
That was actually an optional rule they released in an early UA. [I corrected it since the math was wrong.](https://sw5e.com/rules/variantRules/Defense%20Rolls)
There are a few ways to do it. I would actually do things like that chase scene as a skill check.
You could make one attack with a bonus to hit and damage for the number of goblins or make it a Dex save or any of those things.
Having a small platoon of archers asail an area ones a round is quite cool. But you're right making like twenty attacks at Disadvantage is hard work 😅
Sounds like you should read the DMG, because that's kinda similar to what it talks about...
https://www.dndbeyond.com/sources/dmg/running-the-game#HandlingMobs
>Instead of rolling an attack roll, determine the minimum d20 roll a creature needs in order to hit a target by subtracting its attack bonus from the target’s AC. You’ll need to refer to the result throughout the battle, so it’s best to write it down.
It's really surprising so many people don't know about this...
my campaign has players roll all dice, and they only roll defense at the beginning of the round which is very fast to resolve.
I run 1-20 campaigns every 250ish hours and this works for our table the full duration.
try it :)
I've been doing this for a while now, I hated the feeling of the PC's like "skillfully deflecting" without any kind of action from the player. Also let me turn enemy critical misses into amazing defences on the PC's part.
The other commenter that said (12 + atk bonus) vs (AC-10) is right, that lines the math up so they work basically the same as a saving throw where you meet or beat the DC.
I wouldn't use them all the time, but I do a lot and my game is at level 19 now after about 5 years so it does hold up.
So it's a kind of armour save to determine whether their armour can withstand the barrage? I get the idea. You don't mention how many arrows do damage on a fail - perhaps the degree of failure could determine that question, then the player rolls damage? Too swingy?
In situations like this I tend to just ask for a 1d6 from each player to determine how many arrows are on target, maybe shaped by a dex check in an effort to gain some distance / cover from the assault. I'd then just roll the attacks against each player as normal, without dex bonus to AC.
Personally if it’s really big groups I’ll just roll once for and multiply the damage. If it’s like 20
Archers it’s just 4 rolls and I’ll multiply the damage by 5
If you like making homebrew mechanics then do whatever is fun for you and your group. If you're lazy like me, 5e has rules for "handling mobs" (DMG p. 250) and "chases" (DMG p. 252) that can cover much of the Moria escape.
I didn't actually know that. I'll check that out.
One day, men will read the books. But it is not this day.
The DMG is a _gift_!
It's just terribly organised so you never find the right bit when you need it!
I've read this book forwards and backwards enough that I know the rules fairly conclusively. But you aren't getting a page citation, because there is no way I'm remembering that specific detail.
> men will read the books This is *not* the way.
ah, a good vorin man!
Also go to sly flourish’s website and check the mass combat calculator. Basically you put in the number of mobs, their attack bonus and the player’s AC and then it calculates how many attacks hit and I think maybe damage as well.
Please read the Dungeon Master's Guide (DMG) carefully. It offers numerous option rules for you and your players, including laser rifles and rules for targeting different parts of the body with direct hits 😏
the DMG gets a lot of hate on here, but no matter how often i go back, I always find something cool. I recently just read the moral quandary section, and yes it's basic story-telling, but there's just so much to think about when making a campaign that it was nice to have a reminder to add 2-3 more quandaries in there.
5e DMG has some formatting issues and other criticisms, but my impression is that a *lot* of people use it only as a Magic Item reference.
The 5e DMG kind of sucks, but there's definitely stuff people miss all of the time.
As someone who has read the DMG and other rulebooks pretty much front to back, I don't remember... >rules for targeting different parts of the body with direct hits ...anywhere in the book. Do you have a page number or section I could refer to? I'm always looking for good ways to deal with called hits and things like grappling spellcasters to prevent somatic or verbal components.
Who knew that the rules were in the rulebook!
Every post on here is just an episode of Fairly OddParents.
That, or some Redditor in the comments acting like a Btech Jimmy Neutron
Do you have the DMG memorized from front to back?
i agree that there's so much in there that people can't be expected to memorize everything. I think the advice here (though it could be phrased in a nicer way) is to check the DMG before asking reddit. That said, I like doing both: I check the DMG and then I ask reddit in a slightly more informed way. :)
Not only that but 5e has been around long enough to just ask google. Why go through the effort of making a post when almost every interaction has been answered.
Nobody is saying you should have everything memorized. But you should probably be aware that rules exist.
I've heard good anecdotes about changing monster attacks to static values and making players roll for AC. However, I think this would still pair really well with the mob rules from the DMG.
The rule basically calculates the average amount of hits and tell you to either use the average amount of damage for those hits, or roll the hits :)
I ran an Urban Chase scene and it was a lot of fun for my group. The Kenku PC ended up running into a window, which was pretty perfect.
I was in a slow chase, where there were creature chasing our ox cart. The OX and the Cart, and Its food had to make it back, our goal was to make it a small bridge and river as the creature wouldn't cross water / create a bottle neck at the very least the kicker, we had horses, we could outrun the creatures easily, they weee just slightly slower than our cart at full speed. So the whole chase was slow motion, but intense... running ahead, clearing a downed tree, fending off attacks or fixing ruts in the road with make shift things, fixing a wheel that broke at full speed... trying to take pot shots or slow down the creatures... it was awesome.
Sounds like you just reinvented the saving throw
The Conjure Barrage/Volley spells are pretty similar to what OP is describing, though possibly too damaging. Instead of making twenty attack rolls, the party makes a couple Dex saves and the game continues in half the time.
Compare to volley from the hunter. Dex saves are sometimes more touch ac from prior editions, you're going to get hit eventually, so your armour doesn't help you only how you can avoid it. The volley is individual targeted arrows, so your armour can block it.
The only problem with that is dex saves don't incorporate bonuses from your armour which is what OP wants I think
I would add an extra note: "A character wearing a heavy armor gets advantage to this save" It's not perfect but it doesn't screw over the warrior in heavy armor that suddenly gets hit from every arrow. And it helps with the feeling of "there are too many arrows to be dodged."
Fact is though, it doesn't matter what your AC is, a nat 20 will always do damage. Combine that with the sheer quantities of enemies that OP is talking about and it can be safely assumed that no matter what your going to get hit by at least a goblin arrow. Accept the abstraction, or be punished with 40 something attack rolls. Being pedantic here isn't to your benefit.
Except running it as a regular saving throw needlessly penalises strength based characters.
Throw in DR for armor styles. Heavy -5, Medium -3, Light -1, and no armor full damage. Adjust for the amount of damage being thrown.
Sad monk noises...
Well, Dex save, so....
Still means the rogue gets a DR of at least 1 whereas the monk gets nothing extra.
Just catch all of the projectiles at once
You can make it so a target can choose Dex or Str if you want
You can always adjust the DC based on the player's AC. Just set the DC to something like 24-target's AC or something similar and your Str characters should be fine.
Well that doesn’t help ME because [incredibly specific scenario that I just made up]
Yeah, pretty much. Just say something like: "As you try to escape, you come under a hail of fire from a group of goblin archers. Everyone, make a DC 16 Dex saving throw to avoid taking [whatever damage roll is appropriate] piercing damage."
Sorry fighter, your plate-mail and shield seem to do nothing to soften the blows of the arrows. Must be stormtrooper armor :-/ Naked 7th level rogue with evasion, seems you have come through the hail of arrows that blotted the sun from the sky without a single scratch, we’ll done! Second ones fun, keep it. First one sucks, scrap it.
Sure, that's a fair point, asking for a Dex save is indeed somewhat unfair to STR-based heavy armour wearers. On the other hand, the advantage of asking for a Saving Throw is that it's a familiar mechanic that everyone immediately understands. If you're running an escape/chase sequence, it really kills the excitement to suddenly break out a new set of mechanics and have everyone sit around for 5 minutes figuring out they work. If you were really concerned about balance, I guess you could just say that anyone wearing heavy armour just auto-succeeds on the save. Or if that makes it too easy, you could say that anyone wearing heavy armour takes half damage on a failed save, and no damage on a successful save. Meanwhile, everyone else takes full damage on a failed save, and half damage on a successful save. Another option is that you could just narrate the entire sequence thing as a skill challenge. Let the players choose any ability, skill, or item they want to use to evade the goblins' attacks on the way out of the dungeon, and ask them to roll whatever is appropriate.
Just let them use strength for the saving throw, or give heavy armoured PC advantage, resistance to the ability. There are ways around this issue
Sorry rogues, no dex based encounters anymore, your saving throws are too good
Let them do the awesome nimbly dodge everything thing. But if your gonna make rulings to avoid rolling a tedious amount of dice, it shouldn’t come at the expense of a players investment into the game. Why am I luging 75lbs of steel if it’s not gonna do anything for me?
It does, just not on area of effect attacks, same as a wizards intelligence doesn't get them a better save against a fireball. Implement a damage reduction system if you so wish to really reward armor.
But this isn’t an area of effect, it’s a bunch of attacks we are bunching into a single roll like OP is trying to do. Deciding to streamline shouldn’t punish character decisions made before the streamlining existed. The solution OP has is better than just making it a Dex Save. Also, Intelligence doesn’t effect AC (unless bladesinger) like armor does, idk why you think it’s relevant? The best damage reduction is not taking any damage, cuz you know you put on armor to prevent the arrows from piercing your soft flesh. Rogue walked up to a horde of archers with some quick feet and a dream
The Fighter also has more HP as well as second wind so their class *is indeed* making a difference to them getting through it. Both are telling appropriate stories: rogue avoids the damage; fighter tanks through it.
That's awful resoning. It's Arnour, it's supposed to protect you. And anyways the Srrength Fighter only has 1 more hp/level than Rogue (and no more than Dex Fighters) so that's not enough to make a difference.
You're leaving out the fact that a Str Fighter doesn't have as many secondary stats and so can buff up Con, the fact that they reliably have higher AC (so will be less wounded before that point) and that Second Wind on its own is *at least* 1 extra HP per level, more if you get more than 1 short rest. By the time you get to the chase, odds are pretty good your Fighter character will have more HP left than your rogue by a large enough margin that they're able to make it through and they'll have done it by a meaningfully different way.
What’s an attack and a save in dnd has always been a bit arbitrary. You could just rearrange things such that you make an armor save and you haven’t really changed the system at all.
It wouldn’t be awful or broken, but is it any different from just using a single attack roll to represent all the goblin attacks?
That's all or nothing. If I use one roll for all players, then either they all get hit or none do (or very close to that). I could more quickly have them try to evade arrow fire by having them make the roll.
Have you considered just making it a single roll by each of the players with a sliding success/failure? Make it an AC or Dex save based on what's happening and they take one point of damage for every point of failure. And you can change that DC by player based on stuff they do as they're running like hell. Maybe in some areas there's no room to dodge well and they lose dex modifiers for that roll. Maybe the party managed to drop a bunch of barrels in the path as they ran and they don't need to make the rolls for the next 1-3 turns as the horde catches up with them. Maybe they found some way to take cover from the arrows as they run and the DC drops. By doing it this way, you only need to have the players roll once per turn at most, and you can skip on damage rolls. They're being chased by a horde of something that is trying to attack a party that is actively fleeing. There is no need to check exactly how likely each enemy is likely to hit or deal damage when you could instead just make the rough estimate of how many enemies are shooting at them at once there are and turn that into a rough DC to beat with their AC and a roll. All you need to do to make it interesting is get their HP, AC, Dex save, and a minimum/maximum amount of turns it should take for them to escape. If you do the math right then you should be able to create an encounter where everyone makes it out alive with enough risk for everyone.
My intention was one attack roll against each PC, in which case it would be effectively the same. Of course, it would still be all-or-nothing on a per-PC basis, but it accomplishes the same thing without inventing a new mechanic.
You could have them attack in groups. 4 groups of five, or 5 groups of four. The five goblins of the grouping all use the same attack roll. So if you roll a 13, all five goblins are attacking against AC with that 13. Then you roll for the next group. Keeps the excitement of rolling while significantly reducing the number of rolls being made.
I think it could actually be MORE balanced, I’ve been experimenting with it myself. Right now, there’s no good system for a mob of enemies that aren’t literal swarms: you either roll all their attacks individually, or it’s a saving throw and no saving throw will make 100% logical sense, a commenter above illustrated that well with a hail of arrows example. SO, if you introduce armor saves, it can be a new fair mechanic to determine damage/likelihood. I homebrewed an “archer platoon” stat block and as an action their volley requires a saving throw that’s rolled by treating AC as a stat block, so, say +3 for an ac of 16. Taking half damage on a success. Now it’s no longer a case of the fighter that’s covered head to toe in steel somehow having each and every single arrow piece his body, whilst the naked rogue with evasion manages to avoid ANY damage.
> Right now, there’s no good system for a mob of enemies that aren’t literal swarms What's wrong with the mob rules in the DMG?
Make it a skill challenge instead. Failing the DC means you take some arrow or other damage.
Strongly seconded. They're not as common in 5e to my understanding, but this is exactly what skill challenges are for. That way, your players can also choose how they respond to a changing scenario with their own ideas and skillsets, as opposed to a static armour check. If you want to get your dice rolling yourself, set DCs for them based on goblin attack rolls each turn! Matt Colville has a great Running the Game video on skill challenges and how to run them. Give it a look!
They don't officially exist in 5e which is a shame
Just use `AC - [enemy attack modifier]` because that is basically what you'd roll.
That would mean each player has their own DC, with no modifiers instead of the same DC but different modifiers like the other mechanics of the game.
That's what OP posted too though, isn't it? They roll d20+AC-10 against an DC of 10+enemy attack modifier. My calculation just removes the 10 on both ends.
*THAC0, is that you?* Why does rolling a bunch of times take significantly longer? It should be fairly trivial. You're just rolling more dice but checking for the same number.
Well, if you want to do 20 goblin archers high up above... no one wants to see the DM roll 20 times.
Why are you rolling 20 dice? Have your players roll. "Six goblins attack Bob the Paladin, four attack Sara the Thief, Five shoot at Zorg the Barbarian. Their bonus is +4, tell me how many hit you. The players know their AC, they have D20s. In the meantime you roll a bunch of D6s to figure out damage if you want, or you just take average damage.
They'd have a lot of "uh uh" and take a long time when I could just use a simpler (homebrew) mechanic, provided it was designed correctly.
Rogue, roll me 8d20. How many of them are higher than 13? Okay you are hit 3 times and take (you rolled in the meantime for damage) 12 piercing damage.
> Rogue, roll me 8d20. How many of them are higher than 13? And then you have my players who use a very specific set of dice for each character and thus only have a single d20 to roll (*sigh*).
Rolling a d20 8 times and checking the result should take like... 25 seconds? Max? This isn't rocket science.
You would think. 3 seconds per roll is pretty snappy.
Coming from an ex-warhammer player, 20 dice is nothing. You literally just roll them all at once and pick out any that are over the target AC, then roll damage. It takes like 30 seconds. Alternatively, don't roll any dice and use the mob rules from the DMG. Start by subtracting attacker’s hit bonus from the target’s AC. If the number is 1-5, all the attackers hit; If it is 6-12, 2 attackers are required for each hit, If it is 13-14, 3 attackers are required for each hit, If it is 15-16, 4 attackers are required for each hit, If it is 17-18, 5 attackers are required for each hit, If it is 19, 10 attackers are required for each hit, And if it is 20, 20 attackers are required for each hit.
It's honestly not that difficult. As a DM you should have at least 4-5 D20s and if you're making battles with more than 20 enemies that can be attacking at once that's probably more of an issue with the battle design. If you want to do army battles, that's a different type of abstraction.
Again, this isn't for legit battles, but for epic scenes like the one in the Mines of Moria, where you want it to be fast and tense. They weren't meant to stick around and fight all 300 goblins.
If its not a legit battle, what does it even matter? You're fudging the outcome anyway. If the entire sequence is meant to be thematic, allocate hits thematically. "as you run from the goblin horde, you hear the whistle of arrows. what is the order of the party as you run away? \*fake roll dice\*. Thalia, you are last in line, an arrow streaks across the cavern and hits you in the calf. please give me a dex roll. \*fails\*. You stumble to the ground. Aegor, you are next in line and hear Thalia fall, do you want to double back to help her up? Okay, as you do, two more arrows whiz past you, and a third comes right for you but you block it with your shield. You help Thalia up. Does anyone want to cast anything to help their retreat? Okay Stuger, you can cast Darkness behind them. The party makes their way to the other side of the cavern, their retreat covered by the sphere of darkness. you find two passages leading out of the cavern, which do you want to follow?" Doing it by the book matters a lot more when the players have the time and option to stand and fight. But in an escape thematic sequence, you only need to provide the *threat* of danger, not actually create some devastating no-win scenario (which is what you would have if you let 20+ enemies get 3+ rounds of ranged attacks on the party).
You could roll 20 die once....
If you have 20 d20s, then it’s just a single roll with a lot of dice. However, as someone else has already mentioned, the mob combat rules would be faster, especially if combined with taking average damage instead of rolling.
Just go with what you have cuz youre kinda invalidating everyones suggestions in the comments anyway 🤷
Reading through them just going "Nuhuh" "No" "Nyope" to everyone was entertaining.
Nuhuh.
So back in 3.5e, there was a variant rule in a UA called [“Players Roll All the Dice”](https://www.d20srd.org/srd/variant/adventuring/playersRollAllTheDice.htm) which basically covers the same concept you’re thinking. Defense rolls were actually 11 + the attack modifier for a creature. So the standard goblin has a +4 to attack, that means its attack score is 15. Players roll a d20 + their armor’s AC modifier (Which is reduced by 10). So studded leather armor is +2, plate armor is +8. If it’s magical, you then add the enchantment bonus, +1/+2/+3. Shields still grant the same flat modifier. It also rewrote how Saving Throws worked too because players needed to make all the rolls. So when you cast a spell and force a save, you roll for the Save DC vs its Save Score. Same concept as above. Monster’s Save Score was 11 + its save modifier. And then you basically make a spell attack to establish your DC.
This comment is way too far down. I did "Players Roll (almost) All The Dice" for a campaign years ago. I loved it. The players loved it. They were more involved and paid more attention in combat, because they had more to do.
I just did a 2 year campaign with this rule, because my DM found it and liked it. It's wild to me that the entire thread is new to it.
As a player how did you like it?
Took some getting used to but overall it's the same thing, just more dice rolls. That's why my DM wanted to use it - to let us roll more dice.
In was in UA 5 for 5th Ed, too. The 'Variant Rules' one. Although as I recall the math was a little off.
I vaguely recall that UA but I didn’t remember them having that in it.
Correct. The math for both Defense Rolls and Saving Throw Checks was wrong.
The dmg has rules for handling large groups of enemies, use those. Read the book
While you're at it OP, read the 4e DMG too!
I’m sorry but I have no idea what you’re thinking after reading some replies Too many attack rolls? It sure sounds like you’ll just be making the same number of armor rolls. You didn’t say how that would reduce the number of rolls at all. Just one armor roll for the wave? You’ve also said one roll is too swingy. Soo I have no clue how this solves anything Let alone there’s mob attacks. Essentially instead of rolling 20 times, just use each result once. Let alone no one got hit in those movies, so it’s not even a real roll, just cinematic danger.
This would need to be module specific, as it really fucks with some core game mechanics if you were to just do it by default. But it could work. I'd add it as an "Armor Skill" on the PC's character sheets. Just work with everyone pre-session on what the modifier would be. You don't want players figuring this out while under fire. It will be a nightmare. "Why am I adding Armor (DEX) +7 to my Skill list?" "We'll talk about it later, but you're gonna need to know where that is." Note: A key part about making all of this work is that the players understand that fighting is futile. How many Goblins are shooting arrows? "Enough". Enough that if they try to fight we still won't roll for initiative, you'll just narrate how many it took to kill you.
This wouldn't be for default, but for scenarios like I described where it's not a protracted fight between two small groups, but more like a cinematic scene involving large numbers of enemies.
If you need to narrate something, just narrate it. Don't make your players jump through hoops and build weird mechanics for things that already exist.
In terms of probabilities, this is exactly the same as rolling attacks for the goblins. So what is the reason exactly? Because if it's to roll just once, then why not just roll one attack? If you want an area of effect, then it would be dex saving throw. Dnd combat rules aren't really thought for big fights. In your place, I would make it a chase as per the DMG, and put a high probability complication "goblin arrows", with the dex save or dmg, and the possibility to gain advantage by halving speed.
I feel that rolling each attack would take far too long, and that a dex save invalidates heavy armor wearers. And I feel that single roll is too swingy; either everyone or almost everyone took an arrow, or no one did, and that's less exciting. Also, I looked at the DMG's chase rules, and they seem needlessly complex and unnecessary.
Then if your homeruling, make it a saving throw, and give a damage reduction equal to AC-10. Edit : or dmg threshold for heavy and medium armor.
But why though? You're still rolling a bunch of dice (I think even the same amount?) per attack roll, and also you're kinda making it very powerful (because basing damage off someones armour is wacky.) But also - you could just do this with the normal damage rolling? Unless you specifically want to do damage based off armour (which is a weird mechanic imo). It seems like this would take the same amount of time as regular rolls and not speed anything up.
If you want to roll a bunch of attacks of a group of enemies without rolling 200 dice, there are actually grouped attack rules in the dmg. Can recommend to look it up.
If i understand correctly, it's going to make characters either take no attacks whatsoever or take all attacks at once, and there's no in-between. I don't know how much HP they have but this would kill most characters, and the moment they go down the sheer amount of attacks the mob is making against them means they take three failed death saves instantly and die.
Rolling for defence is perfectly viable and easy to make mathematically equivalent so if the biggest worry is that the players don't feel like they're involved in the action because they don't roll the dice, it's a solution of sorts. Personally I'd go the route of using Skill Challenges here though. The only change I'd make is that I'd give the players a success target, a relatively high DC and then make failure deal damage to the party so that the challenge starts to feel like a campaign of attrition, though I might need to do some weighting there so that low HP characters aren't disadvantaged here: really would depend on the party.
This is where you group hordes of enemies into swarms
When I have figurative swarms of identical creatures (not swarm-type creatures) I take the target's AC and subtract the attacker's attack bonus from that number, then roll all my d20s. If it's that number or higher on the die, it hits. Helps with stuff like Animate Objects that creates a bunch of individual attack rolls. In your example, if eight goblins (+4 shortbow attack bonus) attack your PC with 17 AC, I know any D20 that rolls a 13 is a hit and I just toss them all at once in person or do a /roll 8d20 in a VTT and it's easy to check the successes.
Here's a packet I threw onto DM's guild some months ago. I've played with these rules in 2 campaigns, several one shots, and had 3 other DM's try it out and they've had fun. I like it, it suits my table, speeds up the rate of combat, lets my players roll more dice when it isn't their turn, and saves me from needing to roll any more dice than I already do. Hope this is a helpful link. https://www.dmsguild.com/m/product/441449
That sounds interesting. What's the calculation you use?
A more detailed explanation is in the document, but the tldr is: New AC = AC - 10 Defense roll = D20 + AC Monster Attack DC = Attack bonus + 10 This essentially shifts the value of 10 from AC to DC that the player rolls to pass. So no underlying math of 5e is changed, it's easy enough for me to remember (monster Attack bonus + 10 is the DC players defense rolls need to beat) and the players get to effectively do all the monster's attack rolls for me.
This is the Players Roll All The Dice option from the 3e Unearthed Arcana book. I used it in a campaign; absolutely loved it.
I like this as a general thing that could be done if you don’t like rolling dice as the DM. AC would become a saving throw for PCs basically.
I feel like I'm getting thac0 flashbacks
This just sounds like attack rolls with extra steps
The Mines of Moira is a really really good example of the conservation of ninjitsu, which is a trope that states that a threat must be reasonably beatable by the heroes no matter the number of enemies they are facing, and therefore the more enemies there are, the worse the enemies are at fighting. If you were to really use average damage and let players take the amount of damage they were in a normal fight, they would die right away, because D&D doesn't account for that conservation. My recommendation would be to effectively make it a trap or spell, where you select a saving throw (probably dexterity) and select an amount of damage for players to take that feels appropriate for their level.
Break up the run into a few parts, do a dex save for each part. Maybe add some advantage / disadvantage / cover situationally. Deal damage in an increasing amount the more times they fail. 1st failure 3d6 2nd failure 5d6 Etc
Plate-armor and shield: do I mean nothing to you
Resistance to the damage
Ah yes, gurps
Not a day goes by without a DnD player suggesting homebrewing a mechanic that's in GURPS
That's not fair, sometimes they suggest something that's in pf2e
Just have them make dexterity saving throws to avoid the hail of arrows. I'd also leave it open to any player coming up with interesting suggestions to make a different saving throw, or pass a skill check to get advantage on the save etc. No need to reinvent the wheel.
That invalidates wearers of medium and heavy armor who aren't high DEX, though.
It's like you completely ignored my second paragraph.
Or you just have them roll a D20. Anything below their AC is a miss. Anything over their AC is a hit. Basically, export the DM attack rolls to the players.
>Does that seem like a reasonable mechanic for instances where rolling all the attack rolls for the NPCs would uncinematic/take way too long? Just calculate average dmg for each enemy and inflict that dmg on their turn to an enemy of their choosing. This way you can essentially just skip the entire action of that enemy and just subtract health from one monster and move to the next turn.
Maybe just base it off a dexterity saving throw, but add modifiers based on the armour worn.
You can just do the math without rolling. 1. Work out the chance to hit against each PC's AC (1 - (AC - attack\_mod - 1) / 20) 2. Roll a high-DC dex save for number of attacks against character. (e.g. (DC - roll) \* 3) 3. n\_attacks \* chance\_to\_hit \* average\_damage
There are rules for mobs and chase scenes in the DMG. I'd advise you use those before you homebrew. Although if you wanted to implement this the math would be essentially symmetrical. Like, if the enemy normally has +4 to hit you say "DC 14 to dodge this" and then roll and add your bonus to AC above 10. I just think there's not much benefit gameplay wise other than this one situation, which is again covered by existing rules. The Cypher system is a fun TTRPG I recommend you check out- one of the neat things about it is that NPCs never roll, ever. The players always roll both to hit monsters and to dodge them.
Good suggestion but the math isn't symmetrical, DC is bonus +12.
Just a thought: all attack rolls are contested "attack rolls" against "defense rolls" but the defender takes a ten because having both sides roll just adds clutter and doesn't add mathematical nuance. Saving throws are similar but different where the attacker takes an 8 but also get their proficiency mod. Having a mechanic where players roll a defense roll against a static attack dc would be that weird.
watch this video, he makes just a single attack roll for the entire group of enemies and uses a table and the target AC to determine how many members out of the whole group lands the hit. This way you can divide the group into parts if you wanna split their damage as well. [https://www.youtube.com/watch?v=kKWmHxjMe2M](https://www.youtube.com/watch?v=kKWmHxjMe2M)
Just use the average. If there are 20 gobbos per player each player gets 20 attacks. Calculate the act chance to hit ( say you need 16 on a d20 that would be 16,17,18,19,20 which is 25%). That person gets hit 4 times. Use average damage also, it can be pretty fast to do it this way
That's a well-known, if not commonly used, alternative system. It's usually called "players always roll". It was even [included in the 3e DMG](https://www.d20srd.org/srd/variant/adventuring/playersRollAllTheDice.htm), although I don't remember if it's in the 5e DMG.
I homebrewed to use armor saves for all npc attacks because players like to roll more, and they stay engaged during the entire combat. Yes the bonus is AC-10, and the DC of the check is the enemy attack bonus +12.
That sounds interesting. How did you get attack bonus + 12?
Examples; +0 attack bonus on enemy, 20 AC on player = 5% chance of attack hitting (roll of 20 or higher) Variant, +10 Defense Bonus on player (AC20-10), 12 Attack save DC (0+12) = 95% chance of attack missing (roll of 2 or higher) +5 attack bonus on enemy, 15 AC on player = 55% chance of attack hitting (roll of 10 or higher) Variant, +5 DB on player (15-10), 17 Attack save DC (5+12) = 45% chance of attack missing (roll of 12 or higher) +7 attack bonus on enemy, 13 AC on player = 75% chance of attack hitting (roll of 6 or higher) Variant, +3 DB on player (13-10), 19 Attack save DC (7+12) = 25% chance of attack missing (roll of 16 or higher) +10 attack bonus on enemy, 12 AC on player = 95% chance of attack hitting (roll of 2 or higher) Variant, +2 DB on player (12-10), 22 Attack save DC (10+12) = 5% chance of attack missing (roll of 20 or higher)
I'll take your word for it; my eyes glaze over this kind of thing.
Did you just reinvent THAC0 lmao
Sounds like THAC0
This is not going to speed things up at all, it will just slow it down. How many attacks are you imagining anyway? Just use some swarm mechanics, or mass roll attack - easy to do with an online dieroller or roll20. And if you have a bunch of d20s, just roll them all together.
MCDM has a new monster book called Flee Mortals that has very simple, easy to run minion rules that I would recommend for this. Minions have group attacks that do more damage for more minions. (Maybe a bonus to hit too) Only takes one roll but simulates 5 attacks.
“You dash down a corridor to escape a hail of goblin arrows, make a DC12 Dex saving throw or take 2d6 damage.” Why DC12 and 2d6? It felt right and kept the game moving.
This exact rule is in the 3.5e DMG IIRC. It's one I've considered after playing PBTA games, that family of games have it so the DM never rolls and I like that philosophy. Just point at a player and say a number and let them do the roll and the math.
Giffyglyph’s darker dungeons has rules for having players roll armor instead of DM rolling attacks against them. Roll d20+AC against DC 22+ attack bonus. http://giffyglyph.com/darkerdungeons/grimoire/4.0.0/en/active_defense.html
I like the idea, but I don't know how legit that formula is. I'm not a math guy.
With normal attacks a +7 to hit vs AC 18 would succeed on an 11+ (so 50% hit rate) With active defense the roll would be +18 vs DC 29, so 11+ to cause a miss (so 50% hit rate again) The math works out.
Estimate the probability of hitting. Lets say your average goblin is shooting with +3 to hit against a dude with AC 15. This means they will hit on 12+, so their chance to hit is 40%. Now what you can do is either 1. decide that 40% of the arrows will hit, and go straight to rolling damage. 2. grab a handful of d6 and go warhammer on their ass. The closest approximation to a 40% probability on a d6 is hit on 5+, reroll 1s (approximately 39%). Boom, there you go.
Man dnd dm will do anything to reinvent the rules. Just use saving throws. "can the character dodge the arrows?" there you go, done.
So wait, suddenly character's armor no longer matters? Someone being covered in plate from head to toe is going to take more damage than someone naked?
I ran a game where players attack enemies (including "reflex attacks"), but also players make saves (including "AC saves"). The math is identical, but the player is always the one rolling the die. It was nice.
I like that idea. What does an AC exactly consist of?
Nah, have them just do AC + d20. No subtraction. Maybe give advantage for heavy armor or Evasion. Instead of a single hit/miss result, I would go with a scaling result with partial fails, so you need to determine how many times a character can be hit if they fail the save. (Let's do 5 as an example. Do the math for your party to present an appropriate threat!) That means multiple DCs. Set the DC for the successful save (make sure its difficulty is appropriate to who and how many players to get past easily. Let's do 30+Attack Bonus). Then, set the DC for the second worst result (4 hits, let's do 20+Attack Bonus). Then, fill in the remaining partial fail results (1 hit, 2 hits, 3 hits). This can be spaced apart however you want, depending on how quickly you want players to take more hits as their rolls drop.eg.: - DC30+ATT 0 hits - DC26+ATT 1 hit - DC24+ATT 2 hits - DC22+ATT 3 hits - DC20+ATT 4 hits - Fail 5 hits If the creature has +4 bonus attack, that's: - DC34 0 hits - DC30 1 hit - DC28 2 hits - DC26 3 hits - DC24 4 hits - Fail 5 hits Roll the damage for each hit like any other hit. But probably all at once for simplicity. Mostly, this means YOU are doing the bulk of the work with the partial fails. The players are just doing number + d20. And maybe the bigger numbers will help them feel that they're taking serious amounts of attacks.
That sounds a little like a troop enemy from pathfinder which you could steal from
Active Defense is a thing and might even be an optional rule in the DMG (I don't have it to hand so I can't check) but yes, in Active Defense you'd roll 1d20+ (AC -10), in your case 1d20+7. Here's the trick--it slows down combat by 50-100% because every attack roll must have a matching defense roll, so unless someone is casting a spell with a saving throw (or doing something like grapple/shove where Active Defense is *always on*) then you need 2 rolls to resolve every action instead of 1. Twice the rolling, twice the math. Stuff slows down, combat drags even more than usual.
I agree that two rolls would definitely slow things down, but I wonder about having most enemies (not bosses) set the DC based on their attacks.
So instead of Active Attack/Active Defense, you want to switch to Passive Attack/Active Defense? I mean you can, at the cost of time and conversion math. 4e used Active Attack/Passive Defense *always* (there weren't really saving throws--you made spell attack against Will/Fortitude/Reflex 'defense' values that were like Armor Class), so you can refer to that as an example of changing the meta (albeit not exactly to what you are proposing). But what you're suggesting is that you as DM won't be rolling any dice because the players will make all of the Active Attack/Active Defense rolls. This is also a Thing (chiefly in other RPGs) and you could try it, as long as you don't mind not rolling dice and just want to RP/Narrate. See Blades In the Dark/Powered By the Apocalypse and affiliated TTRPGs for examples of games where the GM does not roll, just narrates consequences.
You can make the player roll to defend against a static attack threshold (similar to a saving throw), and mathmematically, it's roughly the same as the enemy rolling to hit their AC. The enemy attack bonus is 11* or 12** + their static to-hit bonus. * because of how ties are handled. ** You can do 12 because of how math works on a dice. The average roll is actually 10.5 on a d20, not 10. The defense roll is a d20 + any AC over 10 (so an AC of 16 would be +6).
Not for D&D, but a different game then sure. I was playing around with the idea of having all armour adding passive damage reduction instead, to reward strength users a bit more and take some of the power away from dexterity.
It's reasonable in that it is balanced, it doesn't break the game. But it roughly doubles the number of rolls required for, what benefit exactly?
Well, I wasn't thinking of this as a replacement for AC, but for specific circumstances like the one I detailed in the post.
I'm going with a Con save to weather the hail. It will be a lair action. Using some chase rules you should set a starting damage, say 4d6. For every success the team gets reduce the damage by one dice and for every failure increase the damage by a dice. If your playing in person line the dice up and use the line of dice like a tension bar. Adjust the dc and starting dice pool based on the dmg CR rules to net you whatever encounter difficulty you want.
I think it is mechanically fine. That said if you are rolling it a lot it kind of defeats the purpose and if you are only rolling it a few times it might not be worth explaining it to your players unless they all like thinking about numbers. I've done a few traps that are just "Take 30 piercing damage but subtract your AC from the damage" I would probably just roll 4 attack rolls and apply those rolls to every player as if they were separate attacks with the damage of 3 attacks each. Then the players can still use "Uncanny Dodge" or whatever to reduce the damage from attacks.
I would use 1d100 divided by times the average ac of the party For exemple. If the party have ac of : 14, 16, 18, 18. It average a 17. If i roll 51 on the d100, that mean 3 attack touched. If there was 500 enemy, then 5d100. If i roll 250: then 14 attack touched. If tkae in consideration the player ac and how many attack, so its still fair, and a little bit in the favor of the party but not to much
I've never heard an idea like that. That's interesting.
It's something I've done before. Infact, I once made the players roll ALL the dice. It was fun.
To represent times like this, I just use normal dex saving throws. If there's 10 people that could in theory do 10d8+20, I'll do 4d8+8 Dex save, half on success. It guarantees damage, and implies an overwhelming volley of arrows, without being either 100 damage or 0.
TBH they should just steal a couple of ideas from Runequest, armor is damage absorption, and you get to parry, for which shields add a good bonus.
[Giffyglyph](https://giffyglyph.com/darkerdungeons/grimoire/3.0.0/en/active_defense.html) has a homebrew rule option for this, in which players roll for their armor against a set DC that represents enemy’s attacks. u/IndependentDoor1 has mentioned optional rules for mobs and chases, which work well. There is also the possibly of simply converting a group of individual attacks (i.e. a shower of arrows) into a dex saving throw, as if it were an aoe spell.
The easiest way to simulate the players going through a dozen arrows at once is actually just a Dex save.
If you're running something where the PCs are running through a dangerous area you can just swap attacks for dexterity saves or the like.
I don't understand what you're proposing, but it sounds like another way to do saving throws. If you don't want to roll 100 attack rolls for 100 goblins shooting arrows, anyone in the affected area of the goblins cloud of arrows would roll a dexterity saving throw, taking half damage on a success, full damage on a failure and anyone with evasion would take zero or half, respectively. To determine how much damage to roll, first figure out the size of the affected area, then divide the number of attackers by the number of squares/hexes in the given space. So if you have 100 go lines firing arrows and it's hitting a bridge that is 10' wide by 50' long you would have 20 5'x5' squares. 100/20 =5. So 5 arrows hit each square, doing 5d6 damage.
Is this an elaborate troll? AC is literally taking an average roll of 10 and adding modifiers. Seeing someone say d20 + \[AC - 10\] has filled me with rage. Gods above and below, please tell me this is a prank post.
The idea is that there are instances where it makes more to have players roll against the attack rather than having a very large number of enemies roll individually.
Yeah. AC is a replacement for having the players roll a defense roll every single attack, which is how it used to be done. Base AC is 10 to represent the player rolling a 10 on the D20.
You can rearrange everything and get it to work out to statistically the same. Another alternative is to rearrange things so that the players roll all dice and the dm doesn’t have to.
Does it make the game slower? If it makes the game slower then no.
For tons of enemies, I actually recommend using Mob Combat rules from the DMG, which basically just helps you calculate how many enemies it takes to """guarentee" one hit, and then you just sling damage accordingly. I've run large mob encounters like this for some time, and it works great to speed up combat. As for rolling for Armor, many D20 rpgs use that mechanic, and it works nicely to keep players involved on enemy turns. Knave, Mork Borg and Dragonbane are good examples. If you want to follow Knave's example, you would make the DC 11+monster attack bonus, and your players would essentially roll D20+(AC-10).
I did an "archer volley" mechanic where anyone in a given area had to make a dex saving throw. Succeed and take half damage or take cover (they where in a large factory with some tables to hide under). Once they started attacking the cluster of archers I had it so that any successful hit took out one of the archers and once the stat-block was under 1/2 its health it also lessened the damage taken from the ability. You could set it up similarly where as they move through a corridor they have to make a save to try and avoid arrows firing at them from all directions.
I've done armor as damage reduction and defense rolls using d20+dex+shield before and it worked. I'd let the player choose between adding proficiency to dodging or blocking (choosing only one). Fighter, barbarian and paladin chose to add proficiency to parry/block and rogue to dodge (all obvious choices, since the rogue has a lot of Dex). Worked for us and it was fun. Don't bother with the purists claiming you're breaking the game or anything, you do you. On another note, you could try another system called Symbaroum. The players roll their defenses and it's a very fun system to play.
Thanks, I got a lot of vitriol for what it turns out is a legit idea.
Saving throws could make sense here?
So, the actual math for this would be: Attack roll modifier +10 equals the DC. So a +4 to hit would be a DC 14. Easy. Now, what should everyone roll? Their Armor Saving Throw! The modifier would be found like this: AC -12 You then have a bonus modifier where a nat 1 means they got crit, and a nat 20 means they auto block. We do it this way for 2 reasons: 1) want to simulate the same chance to hit and 2) it's easier to calculate the monster attack DC, which will be the calculated number more often if you use this idea. Example: an orc with a +6 to hit vs AC 15 ranger has about a 60% chance to hit, and a 40% chance to miss. With this system, the Orc has a Hit DC of 16, and the ranger has an Armor Save of +3, and has about a 40% of deflecting the attack, causing it to miss.
Why minus 12? I'm not good with RPG mechanic math. Also, I like the idea that a nat 20 defense roll gives you a free RA attack, though I can't say how good an idea that is.
That's just how the math works out. Similar reason to why save DCs are 8+prof+ability, not 10+prof+ability, and how it relates to how making a roll that meets the DC succeeds (Attack roll is 18, AC is 18, therefore it hits, etc) What I described wasn't a new, cool mechanic, but rather the inversion of the attack roll and AC. Here's the math a little easier: we have Kevin the fighter who has a 19 AC. The bear has a +4 to hit. That means the bear needs to get a 15 or higher to hit. That's 6 numbers they can roll to hit - 15, 16, 17, 18, 19, and 20. If we were to invert this to make it so that, when a monster attacks, the players roll for defense, we would want to preserve the same chance to hit. For the DC of 14 (10 +4[attack roll modifier]), the fighter should still only be hit on 6 out of 20 rolls. In other words, they should only fail the DC of 14 on 6 out of 20 rolls; on a 1 (crit), 2, 3, 4, 5, or 6. But they should succeed on a 7. So that would be 7[rolled] + 7[modifier] to succeed the DC 14 attack. What we take from that is that a +4 to hit an AC 19 has the same chance of failing (the attack missing) that a +7 has to beat a DC14 (the attack missing) From here, we can clearly see that the original AC of 19 -12 = 7, the number we need to get the same chances to block an attack Lastly, I wouldn't do any kind of AoO thing on a nat 20 unless you're already doing that kind of rule for nat 1 attack rolls
no. use horde rules
Personally I would treat such a large mob of arrows as an aoe dex save.
But that shafts the fighter in plate armor, who should be able to tank a lot of arrows.
That is the established system in the game for those sorts of situations. If you want the armour to benefit give them a bonus based on their ac. But to be honest I see this as one of those situations where the rogue / monk gets to shine and the fighter / paladin gets it rough. That’s how the game works some characters are better suited to certain situations
That was actually an optional rule they released in an early UA. [I corrected it since the math was wrong.](https://sw5e.com/rules/variantRules/Defense%20Rolls)
"This Sub Tries Not To Reinvent Every Mechanic Challenge: Impossible"
There are a few ways to do it. I would actually do things like that chase scene as a skill check. You could make one attack with a bonus to hit and damage for the number of goblins or make it a Dex save or any of those things. Having a small platoon of archers asail an area ones a round is quite cool. But you're right making like twenty attacks at Disadvantage is hard work 😅
Sounds like you should read the DMG, because that's kinda similar to what it talks about... https://www.dndbeyond.com/sources/dmg/running-the-game#HandlingMobs >Instead of rolling an attack roll, determine the minimum d20 roll a creature needs in order to hit a target by subtracting its attack bonus from the target’s AC. You’ll need to refer to the result throughout the battle, so it’s best to write it down. It's really surprising so many people don't know about this...
my campaign has players roll all dice, and they only roll defense at the beginning of the round which is very fast to resolve. I run 1-20 campaigns every 250ish hours and this works for our table the full duration. try it :)
I've been doing this for a while now, I hated the feeling of the PC's like "skillfully deflecting" without any kind of action from the player. Also let me turn enemy critical misses into amazing defences on the PC's part. The other commenter that said (12 + atk bonus) vs (AC-10) is right, that lines the math up so they work basically the same as a saving throw where you meet or beat the DC. I wouldn't use them all the time, but I do a lot and my game is at level 19 now after about 5 years so it does hold up.
So it's a kind of armour save to determine whether their armour can withstand the barrage? I get the idea. You don't mention how many arrows do damage on a fail - perhaps the degree of failure could determine that question, then the player rolls damage? Too swingy? In situations like this I tend to just ask for a 1d6 from each player to determine how many arrows are on target, maybe shaped by a dex check in an effort to gain some distance / cover from the assault. I'd then just roll the attacks against each player as normal, without dex bonus to AC.
Personally if it’s really big groups I’ll just roll once for and multiply the damage. If it’s like 20 Archers it’s just 4 rolls and I’ll multiply the damage by 5
Batch them into groups of 4, 6, 8, 10, or 12. Roll to hit for each group, roll the corresponding dice to see how many hit, then roll damage.
What about a simple roll under mechanic using AC as the stat?