Hello !
How the stats system on trinity / wow dbc client work ? Where is store the mechanics of main stats (str, agi, etc) and other stats (damage, crit rating, hit rating etc) ?
I am not sure what exactly what you mean by stat system, but “StatSystem” is a good place to start looking.
https://github.com/TrinityCore/TrinityCore/blob/master/src/server/game/Entities/Unit/StatSystem.cpp