RPG Damage Formulas anyone?

One of the reasons I started the Blender’s odyssey almost a decade ago was to be able to make my own FF, Chrono Trigger, and Valkirye Profile games on the near future. Well this is the future where we have engines like Unity and even UE4 along side blender, still I haven’t been able to find relevant information about the damage formulas.

Has anyone know about tutorials, games, or any kind of information that educate you about the matter?

healthPoints = max(healthPoints - damagePoints, 0)

Searching should be useful for this. RPG damage formulas is like A* pathfinding or GLSL shaders in that it’s not game engine specific. Engines can implement or use them for game applications, but it’s more of an “overall game design” kind of topic. You can ask about it here, of course, as well. Many RPGs have damage formulas that are public that you can peruse if you feel the need.

The funny thing is that this is one of the basic concepts of an RPG type game. You can combine different aspects (like cloths) to achieve different effects.

You should really have an idea what rules your game should have.

This does not only belong to damage [I wonder why most games focus on destroying things]. It belongs to other aspects too:

  • travel speed
  • weight
  • carrying capacity
  • size
  • costs
  • dialog options
  • precision
  • strength
  • range
  • duration
    and many more…

Yes, it is a good idea to start with one or two aspects like health and damage. You can add other aspects later.

So think about what you want to achieve. e.g.:
If the character receives damage -> reduce health

now be precise:

healthPoints = max(healthPoints - damagePoints, 0)

if health == 0: -> Game Over

You might want to add an armory aspect:

absolute damage reduction (blocking)
e.g. with a damage reduction of 100 you block 100 received damage points

effectiveDamage = max(0, damagePoints - blockedDamage)
healthPoints = max(healthPoints - effectiveDamage, 0)


percentual damage reduction
e.g. with an armory of 100 you block 50% of the damage received

damageReduction = 100/(100+armory)
effectiveDamage = damagePoints * damageReduction 
healthPoints = max(healthPoints - effectiveDamage, 0)


armory penetration
(obviously an attribute of the attacker ;))
e.g. armoryPenetration of the attacker of 100 reduces the armory of the attacked by 50%

armoryReduction = 100/(100 + armoryPenetration)
effectiveArmory = armory * armoryReduction

You can combine these effects with each other. Be aware the order of the calculation matters.
Make sure you do not get effects you do not want e.g. having enough armory to heal when getting attacked (negative damage).

JRPGs usually have very simple combat mechanics.

Your character has Strength (or Power/Attack/Force/etc)
Your character equips one or more pieces of equipment which increase Attack.
Base damage = Strength + Attack

There is also a Variable, which determines the min-max damage using the above two as the base.

Damage = random between (Base - Variable) and (Base + Variable)

Sometimes, the target will have a Defense, which is subtracted from Damage to get their HP loss.
However, these stats are typically low, and “tough” monsters have higher levels of HP instead. Chopping normal amounts of damage off a monster with 100,000HP is much more satisfying than ticking off 1HP at a time on a “super-tough” monster with 100HP.
Of course, every JRPG has to feature that “Damnit Monster” that behaves like the latter. It is one way to add character to your creatures; an aspect that I think a lot of non-JRPG type RPGs don’t utilize enough. (I’m looking at you, The Elder Scrolls)

What is a “JRPG”?

Java Role Play Game?


I see. I have been reading things like this for a long time. http://www.roguebasin.com/index.php?title=Thoughts_on_Combat_Models
To the point I started to learn Python in order to implement this ideas. But all this information is useful is you know the console inside out. All I’m good for is to print the word nipples all over the console.

A better example: I’m was walking in the street when I saw a rainbow, and from it, a eight color emerged form the middle. It was the most beautiful color I have ever seem. Now, how do you know how this new color looks like when you haven’t see it?

Now I’m a null object if I compare my experience in video game development with you guys, but I bring the next question then, Have you seen all this formulas working properly on blender? because I have seem so many blender games, but no RPGs and they mechanics are very simplistic as well.

Frankly, i’m afraid. I am afraid that the blender game engine would not be enough in order to make a outstanding game, as I haven’t seen one yet.

The bottom line is. If all I will find is documents that talk about a sport but doesn’t show game play, I’m afraid I wont be able to join the team.

Each and every game that let you drop health needs “health = health-damage” (the max is to ensure it does not become negative ;)).

The other formulas are just plain school mathematics (ok, a little bit copied from a fighting game). It is really you who have to define what you want. As usual you can get help in bringing it to live. But you need to discover what you really want. Nobody can do that for you.

No, game engine will ever be enough. Even with a level editor of an existing game you need to put a lot of effort into the game you want to create. The limit is … you.

Anyway this goes off-topic a bit.

I just wanted to say … the formulas are usually pretty simple. But you need to identify what you need than we can help you finding a sufficient implementation.

In the past usually RPG games translated paper and pencil rules (like D&D) in to an electronic format. This didn’t always work, especially when you’re dealing with a real time RPG. Many things that make sense on paper don’t work that well in a computer game.

JRPG, Japanese roleplaying games used quite simple rules, as stated above by @Nines, rather than trying to model all the intricate (but invisible) mechanics of a traditional dive rolling RPG.

Simply put, Traditional RPGs focus on increasing levels and getting skills, development of the character’s nature, while JRPGs usually focus on getting new equipment which augments the character’s base attributes.

These days there’s beginning to become a bit more of a hybrid game mechanics, often more modeled on Card Combat Games (like Magic the Gathering), where you play “cards” which can buff your character in the right circumstance. Having a good character in that case comes down to having a good hand of cards.

If you want to have a good game you need to decide which kind of game you want to play. A really helpful place to look for examples is actually the Roguelike community. A Roguelike being a very simple RPG often written in a short time (it has no art assets and is all about coding), there allows for a large variety of different combat systems. There are also a lot of articlesin the community about things such as combat, magic or other stuff.

When designing a combat system it’s best to make a lot of prototypes and test them thoroughly. Rather than trying to make the whole game and then get people to test it. What might sound like a really good game mechanic inside your own head may turn out to be less than stellar when you make it in to a game.

Some questions to ask yourself when designing game combat mechanics:

  1. How will I make it interesting? Not just button mashing surely? There needs to be something interesting for the player to do every turn. Special attacks can be helpful here, like tripping, disarming, power attack, parry etc…
  2. How will different weapon types be really different? Not just 2d4 damage vs 1d8 damage, but really giving the player an incentive to use different weapons in different situations. It doesn’t matter how much loot you pick up if you’re only using a single type of weapon.
  3. How can I make it so that weak players can still beat a powerful enemy if they play well? There needs to be some kind of force multiplier, or some mechanic for making an extra effort. Like you use all your special attacks and just about beat them, but afterwards you’re really drained. Or maybe magic potions, buffing spells etc… Buffing spells are going out of fashion a bit these days though as no one wants to spend 15 minutes preparing for a fight that lasts 5 minutes by casting every possible buff and drinking every potion. Perhaps permanent buffs are more interesting…
  4. Will there be critical hits and one hit kills? This can be fun, but can also be very annoying when your high level player gets one shotted by a lucky low level enemy.
  5. Will you include lots of hidden subtle game mechanics, like skill checks? If the player doesn’t know what’s going on, maybe it’s not important enough to include.
  6. Will there be weapon/armor wear and tear? Can your sword break?
  7. What happens if you die? Can you be resurrected, do you need to reload? Is death Permanent? This is a very important part of the game and can completely change the way the game is played.

Frankly, i’m afraid. I am afraid that the blender game engine would not be enough in order to make a outstanding game, as I haven’t seen one yet.


It’s made with blender, didn’t play it but watching their threads here on BA and by watching the video’s, wel it’s outstanding enough for me.

Nines: I see what you mean there by… saying, the opposite :confused:. I also played the DAD game. Mechanics are fundamental but for me the more difficult part, I also consider it the most important piece of the game. As for this RPG (work in process)

I don’t have nothing against this kind of work, plus, I applaud the effort. But I’m expecting to see much more(x10). A outstanding game for me is the one that makes you cry every time you listen to the load screen music, the one with such rich characters that you start quoting them to your friends and family and your mirror. (CUE DRAMATIC MUSIC), a outstanding game!!!- ok let me stop there.

By all means, I refuse to died until the day I create a game equivalent to Chrono Trigger story, FF9 world and charisma, valkyrie profile’s Music and damage model, Castlevania SOTN presence, and FF6 nonsense, or just Sabin, I need that guy, somebody give me his cellphone

Sometimes I ask myself, why are you guys (who have 93497% more experience than me in game engines) not making something outstanding?

None of that has a lick to do with engine choice. A good game as you define it can be made in any engine you choose, since it’s basically all skill-based. The plot, dialogue and character development, the background music and storyline, the challenge of gameplay - all of these facets of a game are based on their creator’s skills, not the engine they use. These are things created elsewhere (pixel art tilesets and characters, music and sound files, written stories, formulas) and pulled into the game.

Also, why do you expect to see more? Obviously, not every game can or even should be “outstanding”.

Because realistically, they take a ton of time to make, and most people lack the skill to create even one aspect of such a game.

Most people also lack the drive. Finishing anything at all can be outstanding.

Because realistically, they take a ton of time to make

Come on moon sun, The earlier you start faster you finish.

I just want to see one. Once I see it, it should be fix the next problem

Most people also lack the drive.

With no good examples, no wonder.

Just excuses, stop reading nipples and put yourself to a good use. Remember the day when blender UI looked like alien technology to you? Well, you learned it, didn’t you?

By the way, thanks guys, very helpful. That gives me plenty of homework.