Assuming this question also applies to Nostalrius distribution, not clean TFS, these multipliers seem to have been removed:
TwistedScorpio/Nostalrius (https://github.com/TwistedScorpio/Nostalrius/blob/master/data/XML/vocations.xml)
You may need to change the formula in combat.cpp at Combat::getTotalDamage and recompile the server.
However, it looks like this function is used for both melee and distance fighting here (that's how it was in Tibia, by the way).
If you'd want to separate it somehow, you may write another one, and then change it either inside Combat::closeAttack at this line:
Code:
int32_t totalDamage = Combat::getTotalDamage(skillValue, attackValue, fightMode);
or inside Combat::RangeAttack at:
Code:
combatDamage.value = Combat::getTotalDamage(skillValue, attackValue, fightMode);
Unless you only want to add a multiplier as M0ustafa proposed, and not completly rework the whole formula, then it should be fine to do something like this:
Code:
= Combat::getTotalDamage(skillValue, attackValue, fightMode) * 1.5;
Keep in mind it's written under integer variable, if you care about rounding.
Hope this helps.