There isn't exactly any truly "self playing" mode, but you can always set up a fortress and then just see how long it runs before falling apart. The dwarves al

There isn't exactly any truly "self playing" mode, but you can always set up a fortress and then just see how long it runs before falling apart. The dwarves all have their own needs that they'll try to deal with on their own, and you can assign standing orders for things like farms and food production, as well as guard schedules and patrol routes for basic defenses. There's also the worldgen process which is probably the closest, but doesn't really let you inspect anything while it's happening. The "legends" gamemode lets you explore the history of the world after it's been established, and there's some 3rd party tools to make exploring the maps and timelines a little easier.