need help with critical strikes..... (DAMAGE)

[Monkuar]

example:

 
//Calculate monster damage...
$monsterdamage = rand($monsterdata['damage']/2, $monsterdata['damage']);
if ($monsterdamage == $monsterdata['damage']/2){
$monstertext = ' missed <i>part of</i> his attack, dealing '.($monsterdata['damage']/2).' damage!';
}else{
$monstertext = ' hit you with '.$monsterdamage.' damage!';
}

Example if $monsterdata['damage'] = 10 or 20, it works fine, but if it's like 500 or 200, the chance for it to equal the same is very LOW.

 

I'm looking for something like:

 

-> 10% chance to deal Critical strike (*2) regardless of the $monsterdata['damage'] variable, even if it's over 9000.

 

-> 20% chance to deal a finishing blow(*2.3) damage, or whatever, you get the idea? Any help? Thanks!

 

 

I'm just confused because if the  $monsterdata['damage'] is like 5000, how would I calculate of this number having a 10% chance to do a critical strike as in-compared to  $monsterdata['damage'] mob being just 250 damage? LOL I'm lost

[Monkuar]

actually found my solution

 

http://forums.phpfreaks.com/topic/10156-percentage-chance-of-something-happening/

 

 

did a bit of searching xD

 

edit: mod can close this, sorry