Gamemode in the addons directory.

I was just wondering if you could put a gamemode in the garrysmod/garrysmod/addons/ directory.

Like if I were to put a gamemode in …

garrysmod/garrysmod/addons/AddonGMODEtest/gamemodes/MyGamemodeFolderHere

Would it work?

Nope.

Is there a specific reason why it wouldn’t?

Would you expect petrol to work in a diesel engine?

Garry’s Mod loads its gamemodes through the /gamemodes/ folder. When it loads lua, models, sounds, and other files, it’ll also check the /addons/ folder for content, but will not do it for gamemodes.