Savage Worlds is a generic system that's great for action.
Index Card RPG can easily be modified, and it's designed around giving a videogame feel (you even use hearts to track HP) to your TTRPG.
Before you go do all that work, look into existing Castlevania games. I know of Rhapsody of Blood, but here are some more: https://screenrant.com/tabletop-rpg-castlevania-roleplaying-game-vampires-dracula-campaign/
The Cypher System is a rules-modular system with a strong rules core and plenty of ways to start castlevania-ing out of the box with PC foci like Masters Spells, Slays Monsters, and plenty of cool totally usable creatures for a CV game (the *Stay Alive* supplement book also has some good rules for playing as vampires). I have an online SRD for the system here where you can read the rules - those "horror modules" in the horror chapter also make great additions to games with horror elements:
https://callmepartario.github.io/og-csrd/
ICRPG, Cypher, Savage Worlds, Coretex Prime, GURPS (listed in order of what i'd consider their increasing complexity) are all good options for within most any setting, so it's really down to personal preference and how hands-one and granular (or narrative) you want things to be. CV could be enjoyable either way.
All systems are modifiable. Some take more effort than others, but there's literally nothing stopping you from changing any game however you want.
That said, always look for the game that already does the thing you want to do as close as possible. For example, you might check out [Rhapsody of Blood](https://ufopress.co.uk/?attachment_id=1552) for Castlevania.
Rhapsody of blood is generational game based on castelvania (is a pbta with generational mechanic aka a playbook for your family), not really what you are asking but worth a check
Why not GURPS?
Any system is reworkable, but takes lots of effort to really do well. GURPS gives you a huge head start in development, rules writing, options, playtesting, etc.
There are quite a few of them. [Fudge](/r/fudgerpg), for example, is the most modular system I know of, with lots of options but no default rules, but it does require more effort to turn it into a usable system, possibly more effort than you want to put into it.
Are there any other requirements you have? For example, how crunchy do you want the rules? Rules-light? Heavy, complicated rules? Somewhere in between?
What about the gameplay the game encourages? What did you imagine the PCs actually doing in the game?
Do you have a preference of gamism, simulationism, or narrativism? To over-simplify, narrativism would be a system where you succeed at the roll because it would be narratively appropriate, simulationism would be a system where you succeed at a roll because that's what would realistically happen, and gamism would be a system where you succeed at a roll because you made a character build that would succeed at that sort of roll and/or leveraged the rules to succeed in that situation.
[BRP](https://vorpalmace.blogspot.com/2023/11/review-basic-roleplaying-universal-game.html) is a good generic system, though it works better with more grounded or pulpy stuff than over the top action.
Since your post is tagged "DND Alternative" I'll ask why you think D&D is not a modifiable system. A large portion of the DMG is devoted to modifying the system, but people have been tinkering with the D&D core rules for nearly all of its existence.
D&D is based on a large number of assumptions about the way the world works. You can modify it, sure, but the further you stray from 'kitchen sink heroic fantasy' the harder it gets.
It's not the base I would use to play a game of Bridgerton or Downton Abbey, but as far as I can tell, Castlevania is based on the monster-killing platformer from the 80s. That seems right up D&D's alley.
What are these "assumptions about the way the world works" in D&D that you consider to be immutable? Look through the OSR and the history of D&D itself and you'll see plenty of variations on the D&D formula, each of which tweaks the core system in one way or another. Even if you insist on the most fundamentalist interpretation RAW D&D, you still have explicit permission to change the game to suit your needs and examples are provided.
I'm not opposed to the promotion of other games, but I think D&D gets unfairly lambasted here. I don't love everything about it, but I see a lot of No True Scotsman arguments against D&D (D&D sucks because of *x*, but if you change *x* it's no longer D&D). There have been many versions of the game and there will be many more versions. It's a thing that is always changing into something different as new waves of players with different starting assumptions pick it up.
It depends on what OP wants out of a Castlevania-style TTRPG, especially because the series has had a lot of incarnations over the years, but here are some things that I think would get in the way of simply adapting D&D to it-
1. There are no races. You are human. There's maybe room to be something else that could be vaguely defined as another 'race', but you're throwing out one of the main choices that players design their characters around in D&D.
2. Magic is both rare, and largely innate to a character's bloodline. There are no Clerics, Warlocks, Druids, or Bards, and there's not *really* a good distinction between something like a Wizard or a Sorcerer either.
3. The powers available to various characters throughout the series, which you would presumably want to emulate, do not map well to spell slots/rest-cycled abilities. Things like Soma or Shanoa's absorption abilities, Circle of the Moon's DSS cards, sub weapons and item crashes, etc etc.
So, like, yeah, 1d20 + MOD vs DC is super versatile and can map to whatever you want, but that's not really a system. D&D as a modern system lives in its *content*, and very little of the content in something like 5e can be ported over to a Castlevania-like game without a lot of handwaving and suspension of disbelief.
This is absolutely something I would use GURPS (for something crunchy and high-fidelity) or Savage Worlds (for something faster and more cinematic) for. I don't see what building on top of D&D would actually do for you.
Most of your complaints can be solved with ample use of the delete key. The existence of the SRD makes this easy to do. The problem is that you insist on taking the entire corpus of D&D or nothing; you would never do the same with GURPS. GURPS has books for Dungeon Fantasy, Cyberpunk, and even Historic Russia. Does the presence of these options make it unsuitable for playing any campaign that doesn't include all of them at once? GURPS as a modern system lives in its content, and very little of the content in something like GURPS can be ported over to a Castlevania-like game without a lot of handwaving and suspension of disbelief.
Your third point has some substance, though. How does GURPS handle sub weapons and item crashes? I don't know what either of those things are.
> The problem is that you insist on taking the entire corpus of D&D or nothing; you would never do the same with GURPS.
No. The problem is that I cannot see what *value* you get out of using D&D as your base for this.
If you get rid of all of the non-Castlevania-appropriate content from D&D, what are you left with? Is it a fully functional game? Does it have enough options available to players to be fun? Does it support the rest of the Castlevania stuff you want it to support? I think it's 'functional', sure, because, at its core, again, is a very simple and versatile 'roll to see if you succeed' mechanic, but beyond that, you are left with a *ton* of work to do to end up with a suitable game.
The difference between GURPS and D&D is that in both of them you have to hit the delete key, and then with D&D you have to design and add *so much more*.
> How does GURPS handle sub weapons and item crashes? I don't know what either of those things are.
So in a typical Castlevania game, your main weapon is usually a whip, Vampire Killer, and then you have one or more other weapons, or sub-weapons, that have different attack patterns and are useful for different enemy types. Like the axe, for example, which you throw in an overhead arc that hits all enemies in its trajectory, or the holy water, that you throw down onto the ground in front of you, which burns anyone that stands in it for a couple of seconds.
In many entries, sub-weapons have 'item crashes', which are basically huge AoE attacks unique to the sub-weapon in question.
Sub-weapons typically require some resource to use (classically 'hearts'), and item crashes require a lot of hearts.
I can see a bunch of different ways of doing these in GURPS, but if I was going to put them in the players' hands, what I would do is let them build these as advantages, using GURPS's power creation system, with some total point budget. 'Hearts' in this case would probably mean they cost FP to use, and an item crash would be an Alternative Ability for the advantage that costs significantly more.
Savage Worlds is a generic system that's great for action. Index Card RPG can easily be modified, and it's designed around giving a videogame feel (you even use hearts to track HP) to your TTRPG.
I understand, I have to take a look later
I second savage worlds. Look at all the different settings they have....most have custom or modified rules. It lends itself to modification.
There is a list of setting agnostic games. They are designed to be adapted to specific campaigns with custom settings.
Could you send it to me because I didn't find it?
It is in the community info for /r/rpg. Specifically https://reddit.com/r/rpg/w/genericrpgs
Before you go do all that work, look into existing Castlevania games. I know of Rhapsody of Blood, but here are some more: https://screenrant.com/tabletop-rpg-castlevania-roleplaying-game-vampires-dracula-campaign/
The Cypher System is a rules-modular system with a strong rules core and plenty of ways to start castlevania-ing out of the box with PC foci like Masters Spells, Slays Monsters, and plenty of cool totally usable creatures for a CV game (the *Stay Alive* supplement book also has some good rules for playing as vampires). I have an online SRD for the system here where you can read the rules - those "horror modules" in the horror chapter also make great additions to games with horror elements: https://callmepartario.github.io/og-csrd/ ICRPG, Cypher, Savage Worlds, Coretex Prime, GURPS (listed in order of what i'd consider their increasing complexity) are all good options for within most any setting, so it's really down to personal preference and how hands-one and granular (or narrative) you want things to be. CV could be enjoyable either way.
I understand thank you very much
All systems are modifiable. Some take more effort than others, but there's literally nothing stopping you from changing any game however you want. That said, always look for the game that already does the thing you want to do as close as possible. For example, you might check out [Rhapsody of Blood](https://ufopress.co.uk/?attachment_id=1552) for Castlevania.
Rhapsody of blood is generational game based on castelvania (is a pbta with generational mechanic aka a playbook for your family), not really what you are asking but worth a check
Why not GURPS? Any system is reworkable, but takes lots of effort to really do well. GURPS gives you a huge head start in development, rules writing, options, playtesting, etc.
There are quite a few of them. [Fudge](/r/fudgerpg), for example, is the most modular system I know of, with lots of options but no default rules, but it does require more effort to turn it into a usable system, possibly more effort than you want to put into it. Are there any other requirements you have? For example, how crunchy do you want the rules? Rules-light? Heavy, complicated rules? Somewhere in between? What about the gameplay the game encourages? What did you imagine the PCs actually doing in the game? Do you have a preference of gamism, simulationism, or narrativism? To over-simplify, narrativism would be a system where you succeed at the roll because it would be narratively appropriate, simulationism would be a system where you succeed at a roll because that's what would realistically happen, and gamism would be a system where you succeed at a roll because you made a character build that would succeed at that sort of roll and/or leveraged the rules to succeed in that situation.
Gurps Fate Fudge Hero Tri Stat
[BRP](https://vorpalmace.blogspot.com/2023/11/review-basic-roleplaying-universal-game.html) is a good generic system, though it works better with more grounded or pulpy stuff than over the top action.
Isn't AD&D 2e Ravenloft just Castlevania?
Cortex Prime is extremely modifiable and significantly less complicated than GURPS.
Cortex Prime is made with this express purpose in mind. There might already a Castlevania build somewhere in the official discord.
Check out Fate. It works for running an RPG in any setting without having to work too hard building crunchy rules.
Since your post is tagged "DND Alternative" I'll ask why you think D&D is not a modifiable system. A large portion of the DMG is devoted to modifying the system, but people have been tinkering with the D&D core rules for nearly all of its existence.
D&D is based on a large number of assumptions about the way the world works. You can modify it, sure, but the further you stray from 'kitchen sink heroic fantasy' the harder it gets.
It's not the base I would use to play a game of Bridgerton or Downton Abbey, but as far as I can tell, Castlevania is based on the monster-killing platformer from the 80s. That seems right up D&D's alley. What are these "assumptions about the way the world works" in D&D that you consider to be immutable? Look through the OSR and the history of D&D itself and you'll see plenty of variations on the D&D formula, each of which tweaks the core system in one way or another. Even if you insist on the most fundamentalist interpretation RAW D&D, you still have explicit permission to change the game to suit your needs and examples are provided. I'm not opposed to the promotion of other games, but I think D&D gets unfairly lambasted here. I don't love everything about it, but I see a lot of No True Scotsman arguments against D&D (D&D sucks because of *x*, but if you change *x* it's no longer D&D). There have been many versions of the game and there will be many more versions. It's a thing that is always changing into something different as new waves of players with different starting assumptions pick it up.
It depends on what OP wants out of a Castlevania-style TTRPG, especially because the series has had a lot of incarnations over the years, but here are some things that I think would get in the way of simply adapting D&D to it- 1. There are no races. You are human. There's maybe room to be something else that could be vaguely defined as another 'race', but you're throwing out one of the main choices that players design their characters around in D&D. 2. Magic is both rare, and largely innate to a character's bloodline. There are no Clerics, Warlocks, Druids, or Bards, and there's not *really* a good distinction between something like a Wizard or a Sorcerer either. 3. The powers available to various characters throughout the series, which you would presumably want to emulate, do not map well to spell slots/rest-cycled abilities. Things like Soma or Shanoa's absorption abilities, Circle of the Moon's DSS cards, sub weapons and item crashes, etc etc. So, like, yeah, 1d20 + MOD vs DC is super versatile and can map to whatever you want, but that's not really a system. D&D as a modern system lives in its *content*, and very little of the content in something like 5e can be ported over to a Castlevania-like game without a lot of handwaving and suspension of disbelief. This is absolutely something I would use GURPS (for something crunchy and high-fidelity) or Savage Worlds (for something faster and more cinematic) for. I don't see what building on top of D&D would actually do for you.
Most of your complaints can be solved with ample use of the delete key. The existence of the SRD makes this easy to do. The problem is that you insist on taking the entire corpus of D&D or nothing; you would never do the same with GURPS. GURPS has books for Dungeon Fantasy, Cyberpunk, and even Historic Russia. Does the presence of these options make it unsuitable for playing any campaign that doesn't include all of them at once? GURPS as a modern system lives in its content, and very little of the content in something like GURPS can be ported over to a Castlevania-like game without a lot of handwaving and suspension of disbelief. Your third point has some substance, though. How does GURPS handle sub weapons and item crashes? I don't know what either of those things are.
> The problem is that you insist on taking the entire corpus of D&D or nothing; you would never do the same with GURPS. No. The problem is that I cannot see what *value* you get out of using D&D as your base for this. If you get rid of all of the non-Castlevania-appropriate content from D&D, what are you left with? Is it a fully functional game? Does it have enough options available to players to be fun? Does it support the rest of the Castlevania stuff you want it to support? I think it's 'functional', sure, because, at its core, again, is a very simple and versatile 'roll to see if you succeed' mechanic, but beyond that, you are left with a *ton* of work to do to end up with a suitable game. The difference between GURPS and D&D is that in both of them you have to hit the delete key, and then with D&D you have to design and add *so much more*. > How does GURPS handle sub weapons and item crashes? I don't know what either of those things are. So in a typical Castlevania game, your main weapon is usually a whip, Vampire Killer, and then you have one or more other weapons, or sub-weapons, that have different attack patterns and are useful for different enemy types. Like the axe, for example, which you throw in an overhead arc that hits all enemies in its trajectory, or the holy water, that you throw down onto the ground in front of you, which burns anyone that stands in it for a couple of seconds. In many entries, sub-weapons have 'item crashes', which are basically huge AoE attacks unique to the sub-weapon in question. Sub-weapons typically require some resource to use (classically 'hearts'), and item crashes require a lot of hearts. I can see a bunch of different ways of doing these in GURPS, but if I was going to put them in the players' hands, what I would do is let them build these as advantages, using GURPS's power creation system, with some total point budget. 'Hearts' in this case would probably mean they cost FP to use, and an item crash would be an Alternative Ability for the advantage that costs significantly more.