I have thought on occasion about a persistent world MMO in which players are the drivers of everything. They guard the towns, build
the towns, grow the food, quarry the stone, fight the monsters, form alliances, control territory, act as quest givers as well as receivers, etc.
To make that work, unfortunately, you need a very high quality of player to take charge of these groups, and I'm afraid that the tendency of players to be evil selfish pricks would overwhelm the game. Also, I can't think of a way to make the game newbie-friendly without some means to restrict griefing that would in turn break immersion.
Let's take a very simple scenario: shopkeeping. If a player wants to set up a shop and doesn't want to spend 24/7 running it, but it can be stolen from when he/she is not online, it makes it almost too risky to be worthwhile. You could have hirable NPC guards but no AI can outthink a player. Conversely, if you have a crime system, can a player just go offline to avoid any consequences, or can they be captured while offline? Either way presents a challenge.
edited 17th Nov '12 9:23:34 PM by Fighteer