This probably isn’t something people want when they’re playing a game, but I think it would be cool if there was an MMO with finite resources. The world is generated once, and then not changed again.

This ore mine has six thousand tonnes of ore, and once that’s all been mined, it’ll make no more.

Mobs are “born” at the beginning of the world, Creationist styles, and they can mate and produce more. But once they’re all killed, that’s that species extinct. Maybe a talent tree could lead to taming some pets, as fighters, or as live stock where they can be bred. Environmentalists might spring up, protecting habitats of animals.

Players can build things in each sector of land, but they never truly own it. It can be taken away by force just like it can be in real life. Maybe a guild of players will get paid in exchange for defending the land?

There wouldn’t be any leveling, per say. The aim would just be to earn as much as you can, gain as much land as you can. Become King? Or maybe a democracy could happen.

Player death should mean something. Something extreme. Both to inspire people to live, and also to not take life away. When the stakes are high, a person will be less likely to go and attack people randomly just to be a dick. If they stand to die, and lose all their stats, money, items, and property maybe they’ll think twice.

It’ll be a cool experiment in social politics, in a world where your property actually means something. If you lose your unique Amulet of +10 Health, you can’t just go and do another rinse and repeat quest. That was the only one in the game.