RMXP(DAMAGE CALCULATION FOR SKILLS)

The default formulas used in the game are in the RPG Maker XP help file. Help->Contents, and there should be a link at the bottom of the first page of the help file that will take you to the battle formulas.

You can download the demo of RMXP at www.download.com which'll come with the entire help file. I can upload the help file sometime tomorrow or so too.

In the meantime, here's this!

RPGXP's default battle system uses the following formulas.

The active battler is represented by A, where the battler who is the target for A's actions is represented by B.

First Hit

Normal attacks:
First hit rate = Hit rate of A's state

Skills:
Attack power F is 1 or greater (physical attack)
First hit rate = Skill's hit rate × hit rate of A's state ÷ 100
Attack power F is 0 (non-physical attack)
First hit rate = Skill's hit rate

Items:
First hit rate = Item's hit rate

If A's condition is normal, the state hit rate is 100.



Critical Hit

Normal attacks:
Critical hit rate = 4 × A's dexterity ÷ B's agility

Skills:
Critical hit rate = 0

Items:
Critical hit rate = 0



Calculating Damage

Normal attacks:
Power = A's attack power - (B's physical defense ÷ 2)
Rate = 20 + A's strength
Variance = 15
Minimum force: 0

Skills:
Skill's force is positive:
Force = Skill's force
+ (A's attack power × skill's attack power F ÷ 100)
- (B's physical defense × skill's physical defense F ÷ 200)
- (B's magic defense × skill's magic defense F ÷ 200)
Minimum force: 0

Skill's force is negative:
Force = Skill's force
Rate = 20
+ (A's strength × skill's strength F ÷ 100)
+ (A's dexterity × skill's dexterity F ÷ 100)
+ (A's agility × skill's agility F ÷ 100)
+ (A's intelligence × skill's intelligence F ÷ 100)
Variance = Skill's variance

Items:
HP recovery amount is negative:
Force = - Amount of HP recovered
- (B's physical defense × item's physical defense F ÷ 20)
- (B's magic defense × item's magic defense F ÷ 20)
Minimum force: 0

HP recovery amount is positive:
Force = - Amount of HP recovered
Rate = 20
Variance = Item's variance


Damage = force × multiplier ÷ 20 × elemental modifier × critical modifier × defense modifier (± variance %)


Elemental modifier: The weakest of B's effective elements corresponding to the action's element(s).
A: 200%, B: 150%, C: 100%, D: 50%, E: 0%, F: -100%
Reduced by half if B's armor or state has a defending (opposing) element.
When there are more than one of the same defending elements, the damage may be halved multiple times.

Critical modifier: Equals 2 when the damage is positive and a critical hit is made.

Defense modifier: Equals 1/2 when the damage is positive and B is defending.



Second Hit

Damage is positive:
B's condition is normal:
Evasion = 8 × B's agility ÷ A's dexterity + B's evasion modifier

Normal attacks:
Second hit rate = 100 - evasion

Skills:
Second hit rate = 100 - (evasion × skill's evasion F ÷ 100)

Items:
Second hit rate = 100
B has "Can't Evade" state:
Second hit rate = 100
Damage is negative (recovery):
Second hit rate = 100



Successful Escape

Successful escape rate = 50 × actors' average agility ÷ enemies' average agility

Or, if you are lazy looking to do it the fast way like me, just get this nifty little tool which also nicely calculates hero damage, and enemy damage, critical hits, etc. Any attacks can be calculated! enjoy

well, just let RMXP do the calculation then...