Take Minecraft. Where you can change the world in anyway. Put it in the "oldest anarchy server" where people honestly try to play the game on equal stakes on equal ground. And holy shit things get insane fast. People still build. People still play. It's like trying to survive in a player-made apocalypse of biblical proportions. The only real rule is that anything that doesn't threaten the server's very existence is permitted.
This server turns every player wizard-hacker in deep subterfuge seeing how far they can push the envelope every day. This is the kind of server where the morbidly curious want to see how psychopaths commit social engineering, exploits worthy of Neo shaping the Matrix that would literally be impossible on any normal server, and regular borderline illegal hacking for amusement. I get a real kick out of this. The kind of server where you have to have hacks on by default, and that's STILL not enough.
This guy has loads of stories like this, here's a great introduction.
https://www.youtube.com/watch?v=vtuSXLM8TQE
https://www.youtube.com/watch?v=wG6uaHAJyAc