Hit detection formula

[Bob423 52]

I'm trying to make a custom accuracy formula, but I'm having some problems.

For the damage formula I used formulas from commercial games like Disgaea 4 as a reference, but the only thing I can find about accuracy is unhelpful things like "hit chance = 1.2 * (HIT/SPD)" I don't know how to put that into my game at all.

 

Also, I'm confused as to why, in the code, there needs to be a first and second hit detection.

Everything seems to work fine when I only use the first one, which comes before the damage formula

The first hit detection looks like this:

hit_result = (rand(100) < attacker.hit)

which i think means, take a random number between 0 and 100. if it is greater than the attacker's hit, then hit_result = true.

 

and then there's this silly thing, which comes after the damage formula:

# Second hit detection
      eva = 8 * self.agi / attacker.dex + self.eva
      hit = self.damage < 0 ? 100 : 100 - eva
      hit = self.cant_evade? ? 100 : hit
      hit_result = (rand(100) < hit)

What are the colons and question marks for?

I don't get it >.<

 

For critical hits it's easy since I just keep the LUK stat between 0 and 100, but the HIT and SPD stats can be from 1 to 255

Maybe I should use an evasion stat so battlers can attack often, but be easy to hit...

Edited October 7, 2013 by Bob423

[Metaclaw 21]

I may be wrong here, but here's what I think is happening.

the 'hit' variable holds the chance to hit, in percents.

first it's set to the skill's hit chance, then the attacker's hit stat is factored in. then RMXP randomly decides if the attack hit, based on the hit-percent. this is a temporary/partial check.

if this initial check results in the attack missing- it misses. but if it results in hitting, other factors are used to decide if the attack hits. so the attack may still miss, depending on the other factors, which are:

hit = self.damage < 0 ? 100 : 100 - eva

factor 1: is the damage negative

I think healing skills use 'negative' values. looks like RMXP makes healing skills always hit (hit= 100)

 

factor 2: the target's evasion

if the damage isn't negative, the chance to hit is set to (100 - target's 'eva'). makes sense: if the target has 10% chance to evade, the chance to hit it is 90%.

 

hit = self.cant_evade? ? 100 : hit

factor 2: can this skill be evaded

if the skill cannot be evaded, the hit chance is set back to 100%

 

hit_result = (rand(100) < hit)

lastly, decide if the skill hit or not, based on the 'hit' percent.

this time it's the FINAL result.

Edited October 6, 2013 by Metaclaw

[Marked 197]

Oooooh I know this one, I think!

 

It's the same in PHP, which I'm totally pro @.

hit = self.damage < 0 ? 100 : 100 - eva

Lemme rewrite this for you in expanded form (in php syntax coz I duno ruby if statements, som imma chuck in some semi colons)

if(self.damage < 0){
   hit = 100 
}else{
   hit = 100 - eva
}

Therefore what we're looking at is a shorthand for an if statement. Simple right? The first one (100) is if the question we're asking is true, and the second (100 - eva) is the value if the question is false. 

[Bob423 52]

so...

 

if self.damage = 0
hit = 100
else
hit = 100 - eva

that's sorta simple i guess, but I still have no idea what good this does lol

Thanks anyway :D

[Marked 197]

Well you did ask :P I didn't read the rest of your post. I'm studying :exhausted:

[Bob423 52]

Don't help while studying then :P

I appreciate it though lol

[Bob423 52]

Thanks, that helps a lot! :D

Guess I don't really need to change it then :P

And now I know what I'm doing when I change the EVA stat :D