Comment by lachtan

In WoW specifically, I'll chime in with some things I know about: - the WoW client contains a lot of stuff in their DBC (DataBase Client) files (for example spells and their effects, talents, achievements, etc), which you can extract (the file formats used are basically unchanged and well known since first WoW came out) - the client also uses WDB Cache files which contain things the player has encountered (creatures, items, quests), and volunteer players then send these files to projects like TrinityCore (probably the best known server emulator), which use them to build databases - for dungeon/boss scripting specifically, there's a lot of guilds competing for "world firsts" on official servers who collect a ton of information about boss behaviour, they then use that to develop addons, which help their players when actually doing the boss. then, when you want to implement the boss scripting in TrinityCore (or other emulator), these addons provide a decent starting point for things like abilities and their times, boss phases, etc. afterwards, volunteers report differences they encounter on official servers vs emulators in boss behavior