If you're talking about "Skill Damage" skill_damage_db.txt is your if else or whatever condition
it made for you to adjust the damage easily, you dont need to edit src which need recompile
just @reloadskilldb
Ex. Sonic Blow 100% Damage
skill_damage_db.txt : set -50% in GVG
*Result* : Sonic Blow 50% damage in GVG
so it's working like
if(map == GVG)
Sonic Blow Damage Ratio = Sonic Blow Damage Ratio / 2
*Result* : Sonic Blow 50% damage in GVG
same result but more simple