Damage Formulas 101

Skunk · 2017-07-28T16:33:52+0900

Please note: A discussion has already been started about different things you can do with these formulas so please direct those comments and question to the appropriate thread. https://forums.rpgmakerweb.com/index.php?threads/rmmv-damage-formula-ideas-and-help.47099/ A link to the list of script equivalents of event commands https://forums.rpgmakerweb.com/index.php?threads/rpg-maker-mv-script-call-list.46456/ Damage Formulas 101 MV Edition You probably wondered how to make a skill do more damage against enemies with a state, or heal more if player has a state, or deal exactly half of enemy's HP. And so on. All of that and more can be done through custom damage formula. Basics: Type - sets what does the formula damage or heal. None - Nothing, no damage will be dealt. HP Damage - HP will be damaged MP Damage - MP will be damaged HP Recover - HP will be restored MP Recover - MP will be restored HP Drain - Deals damage to enemy HP and restores that much HP for attacker MP Drain - Deals damage to enemy MP and restores that much MP for attacker Element - Sets which element to use. Normal attack - means will use same element as weapon. Variance - How will damage fluctuate. E.g. If skill formula says it deals 100 damage and variance is 20%, the skill will deal between 80 and 120 damage. Critical - Can skill critically hit, dealing increased damage by 300%. And now, the actual fun part - formulas! It decides how much damage will opponent take or ally will heal. Let's dissect one of basic formulas that come with RPG Maker MV - Fire 100 + a.mat * 2 - b.mdf * 2 What do things like a and b mean? a - attacker b - defender So if Actor Glasses were to cast Fire on a Slime. a would be Glasses and b would be Slime. Meaning the takes double of Glasses mat (Magic Attack) parameter and subtracts double of Slime's mdf (Magic Defense) parameter and adds that to the 100 in the beginning ofthe formula. E.g. Glasses has 100 mat and Slime has 20 mdf. If we were to convert fomula using those numbers, we'd have - 100 + 100*2 - 20*2, after calculation we see with those parameters Fire would deal 260 damage if there were no variance. But only last number in the formula deals damage. If you had 2 lines of formula. (semicolon ; tells where line ends for the program) E.g. a.atk; a.atk*2 Only a.atk*2 would be calculated for damage. Are there more letters other than a and b for the formulas? Yes. There are variables. Which are used like this: v[ID]. ID - index of the variable. So you could have a skill that gets stronger the higher variable is. E.g. v[10] * 2 - b.def * 3 Is there a way to make skill even more complex, e.g. if some variable is over 100, deal extra damage? Yes, in that case we can use if else statements. How if else statement looks: Code: Code (Text): if (statement) { formula1; } else { formula2; } But how to write it to the damage formula? It only has 1 line! Just write everything together~ Code (Text): if (statement) { formula1; } else { formula2; } E.g.: Code (Text): if (v[10] > 100) { a.atk*4 - b.def*2 } else { a.atk*2 - b.def*2 } Which can be shortened to this if you're using only 1 line of formula. Code (Text): if (statement) formula1; else formula2; E.g.: Code (Text): if (v[10] > 100) a.atk*4 - b.def*2; else a.atk*2 - b.def*2; And you can shorten it even further using ternary operator (my favorite one): statement ? formula1 : formula2; E.g.: Code (Text): v[10] > 100 ? a.atk*4 - b.def*2 : a.atk*2 - b.def*2; Symbols for statements: > - more than = more than or equal to 100 ? 1000 : 100; (If variable 10 is more than 100, it'll deal 1000 damage, else it'll only deal 100) v[10] == 100 ? 1000 : 100; (If variable is 100 or more, it'll deal 1000 damage, else it'll only deal 100) v[10] 50 && v[11] >== 25 ? 1000 : 100; (If variable 10 is more than 50 and variable 11 is 25 or more, it'll deal 1000 damage, else it'll only deal 100) v[10] > 50 || v[11] > 50 ? 1000 : 100; (If variable 10 is more than 50 or variable 11 is more than 50 then it'll deal 1000 damage, it'll only deal 100) v[10] !== 100 ? 1000 : 100; (If variable 10 is not equal to 100, it'll deal 1000 damage else it'll only deal 100) What about parameters to use for a and b? Here's a whole list of them: Current: (All flat numbers, e.g.: 900, 999, 11) level - current level (Actor only by default) hp - current hp mp - current mp tp - current tp Params: (All flat numbers, e.g.: 1337, 7331, 156) mhp - max hp mmp - max MP atk - attack def - defence mat - magic attack mdf - magic defence agi - agility luk - luck XParams: (All decimal numbers symbolizing pe…

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Started by Skunk Jul 28, 2017, 07:33 AM 281 posts Page 13 of 15 View original ↗

ATT_Turan

#241 Jan 2, 2023, 08:26 AM Source

fladdles said:
Edit: removed because I found a more active thread to ask the same question, as this one appears to have been dead a while
Just as a suggestion, there's not much reason to do that. Recent/unread posts show up in the same lists on the site. So unless there's someone who's only working off of notifications from threads they've Followed, we're going to see your post regardless of which specific damage formula thread it's in :wink:
emelian65

#242 Mar 30, 2023, 06:11 PM Source
Theorically, making a check for more than one condition would work with && on it right?

For example:
JavaScript:
a.mp && a.tp >= 35 ? 75 : 40;
Could this work if I need the skill to deal extra damage as long as MP and TP are above 35? Or should I need to do something else?
ATT_Turan

#243 Mar 30, 2023, 06:29 PM Source

emelian65 said:
Theorically, making a check for more than one condition would work with && on it right?
No, that's not correct JavaScript syntax. Each side of the boolean operator must be a complete comparison. See:
W3Schools.com
So you'd do a.mp>=35 && a.tp>=35
Fonixed

#244 Mar 30, 2023, 11:22 PM Source
I'm not receiving any battle damage with this formula I'm not sure why.
Can this be done or do I need to make two different damage formulas with the same name?
JavaScript:
if (a.actorId() === 1) { (v[1] + a.atk * 4 - b.def * 2); } else { (a.atk * 4 - b.def * 2); }
Shaz

#245 Mar 31, 2023, 12:03 AM Source

@Fonixed, try == instead of ===. What's in variable 1?
Fonixed

#246 Mar 31, 2023, 09:34 AM Source

Shaz said:
@Fonixed, try == instead of ===. What's in variable 1?

I've given Variable 1 the value of 25, it's just a random value that I'm using to see if I can get it working.

Also == and === have the same effect in this case. I can deal damage but not receive any.
ATT_Turan

#247 Mar 31, 2023, 12:44 PM Source

Fonixed said:
Also == and === have the same effect in this case.
With RPG Maker they always will. Unless you manually set a variable to something weird, they will always be numbers and not need to be a strict comparison.

Fonixed said:
I can deal damage but not receive any.
Because enemies don't have an actorId() field. When an enemy uses the skill, calling actorId() is undefined and zeros out the entire formula.
kn1000a

#248 May 24, 2023, 12:21 AM Source

How much of these can be applied on VXA? I know MV uses javascript but idk how much I can reference, I could not find a comprehensive "Damage Formula 101" for VXA (Forma wrote one but it was not as in depth with each functionality)

Are these functions here like currentExp() the same in VXA? Would've be so nice if VXA let me uses as much as what is documented here.
ATT_Turan

#249 May 24, 2023, 01:59 AM Source

kn1000a said:
Are these functions here like currentExp() the same in VXA? Would've be so nice if VXA let me uses as much as what is documented here.
No, VX uses Ruby for scripting while MV/Z are coded in JavaScript - two completely different languages.

You can look up the VXAce script call list for functions to use in that engine.
Script Call Collection for VXAce
Lisanthius0705

#250 Jun 16, 2023, 01:21 PM Source

Hey, I'd like to make a damage formula that allows me to hit an enemy and at the same time give back a fixed number (for example) 7 of mana and TP to my allies and myself. Is it possible to do this?
ATT_Turan

#251 Jun 16, 2023, 02:17 PM Source
Lisanthius0705 said:
Hey, I'd like to make a damage formula that allows me to hit an enemy and at the same time give back a fixed number (for example) 7 of mana and TP to my allies and myself. Is it possible to do this?
Yes, but it's generally not best practice to put that in the damage formula.

The first post of this thread lists the functions for gaining MP and TP. You can use the forEach() method to do it to everyone. For example:
Code:
a.friendsUnit().forEach(battler => battler.gainMp(7)); damage formula
However, if you give that skill to enemies or you ever use the auto battle trait, it can produce unexpected results. So it's better to use something like Yanfly's Skill Core to execute code like that only when a skill is actually used.
Zakarijazh

#252 Jul 1, 2023, 08:09 AM Source

So i thought I could make a formula that drained 35% of a target's TP and restored it to the user but I feel like I'm missing something?

a.setTp(a.Tp * .65); user.setTp(user.Tp + (a.Tp * .65)
ATT_Turan

#253 Jul 5, 2023, 04:43 AM Source

Zakarijah said:
So i thought I could make a formula that drained 35% of a target's TP and restored it to the user but I feel like I'm missing something?

a.setTp(a.Tp * .65); user.setTp(user.Tp + (a.Tp * .65)
There are a few things wrong with this.

1 - There's no such property as "Tp". It's "a.tp" or "b.tp," etc.

2 - As described in the first post of this thread, the last thing in your formula must always be the value being used for damage. The setTp function does not return a value, so you're going to be getting undefined from all of that.

3 - There's no such thing as user in the damage formula - I'm not sure where you're getting that from. You might be confused with the documentation for plugin notetags, but the damage formula only has a and b.

4 - Your syntax is incorrect. The second statement (after the semicolon) has two open parentheses and one close.

If this skill is not supposed to do any HP or MP damage to the target at all, you probably don't want to use the damage formula for this. You must have a value if you do, which means if nothing else you'll see a 0 damage popup every time you use the skill. If that's the case, you'd be better off using something like Yanfly's Skill Core and putting the code into an After Eval notetag or something like that.
Zakarijazh

#254 Jul 5, 2023, 06:26 AM Source

ATT_Turan said:
There are a few things wrong with this.

1 - There's no such property as "Tp". It's "a.tp" or "b.tp," etc.

2 - As described in the first post of this thread, the last thing in your formula must always be the value being used for damage. The setTp function does not return a value, so you're going to be getting undefined from all of that.

3 - There's no such thing as user in the damage formula - I'm not sure where you're getting that from. You might be confused with the documentation for plugin notetags, but the damage formula only has a and b.

4 - Your syntax is incorrect. The second statement (after the semicolon) has two open parentheses and one close.

If this skill is not supposed to do any HP or MP damage to the target at all, you probably don't want to use the damage formula for this. You must have a value if you do, which means if nothing else you'll see a 0 damage popup every time you use the skill. If that's the case, you'd be better off using something like Yanfly's Skill Core and putting the code into an After Eval notetag or something like that.
okay, thanks. I'll try to do something with the skill core. I did some other stuff but I'm not good as coding at all, so it's... a process. lol
Disponi

#255 Jul 9, 2023, 08:59 PM Source

I want to make an item that has double strength in battle. How would I go about checking to make sure I'm in the Battle Scene?
ATT_Turan

#256 Jul 9, 2023, 09:07 PM Source
Disponi said:
I want to make an item that has double strength in battle. How would I go about checking to make sure I'm in the Battle Scene?
Code:
SceneManager._scene instanceof Scene_Battle ? original formula : stronger formula
Disponi

#257 Jul 9, 2023, 09:18 PM Source
ATT_Turan said:

Code:
SceneManager._scene instanceof Scene_Battle ? original formula : stronger formula
Thanks, that did it! Had to swap the formula places, though.
ATT_Turan

#258 Jul 9, 2023, 09:49 PM Source

@Disponi Oops, sorry, yeah, quickly typed that backward :stickytongue:
mahadeva

#259 Aug 19, 2023, 09:27 AM Source

I'm not so good in formulas. Could you please explain me one thing. Is it possible to create formula that will change damage to heal or heal to damage depending on state or something like that? I'll be very grateful.

Right now I'm trying to create a classes that normally heal characters but damage undead enemies with the same skills. I already know about Silv Undead plugin but I'm also using FROG Health which demands special fomulas written in the plugin options. In other case it's bugging the game. Silv's Undead works only with straight formulas like a.atk and so on.

Found what I need in the another thread. Won't bother. Will just create damaging skills for my healers.
Dark_Ansem

#260 Sep 15, 2023, 03:33 PM Source

mahadeva said:
Found what I need in the another thread. Won't bother. Will just create damaging skills for my healers.
What was the solution?