We have once created a "Clan" or "Guild" addon for gmod, basically teaming up, collecting points, redeeming them for ingame titles, hats, skins etc ( no pay to win tho). Other features were clan wars, which took place during the gameplay like this: -2 points for clan that killed a teammate, +1 for every innocent kill by traitor, +2 for every traitor killed by innocent. It was quite a blast back then.