gistfile1.cs

double GetPvESpellHitRate(byte playerLevel, byte targetLevel, byte spellLevel, uint attackerCount)
{
	double hitrate;
	if ( playerlevel > targetLevel) // Player > Mob, no base miss rate, 0.5% miss per spelllevel lower than moblevel
		hitrate = 1 + (spellLevel - targetLevel)/200);
	else if ( targetLevel == playerlevel) // Player == Mob, 15% base miss rate, 0.5% miss per spelllevel lower than moblevel
		hitrate = 0.85 + (spellLevel - targetlevel)/200);
	else // Player < Mob, guessed formula
	{
		if ( spellLevel > targetLevel) return 1; // Just a safety check so we don't sqrt a negative number. this should never happen as a player cannot have higher spells than his level is
		hitrate = 0.85 - Math.Sqrt(targetLevel - spellLevel) * 9 / 100;
	}

	if (attackerCount > 1)
	{
		attackerCount -= 1 // remove one, as we want the number of additionial attackers
		hitrate += attackerCount/200; // 0.5% extra hitchance per attacker
	}

	hitrate > 1 && hitrate = 1; // cap at 100% just to be sure
	hitrate < 0.55 && hitrate = 0; // any hitrate < 55% results in 0% hitrate

	return hitrate;
}