I've been thinking about ways in which multiplayer could be implemented into Dwarf Fortress. On the surface it seems like the most multiplayer unfriendly game ever, but I think there is one way which might actually work. A single world file on a server that anyone can play on and add their own fortresses to. The world file would update with any changes players have made, so on the world map people could see all the different fortresses created by other players and (possibly..?) go explore them for themselves in adventure mode.
The only problem would be how the world gets updated. Would it update in real time? Or would everything update all at once at a specific time of day, as if everyone logged off at the exact same time. For example if someone playing in adventure mode stole an artifact from someone elses fortress, it wouldn't be shown for that other person playing in fortress mode at the same time. Then when the world file updates, the artifact would have disappeared from the fortress with no reason as to why, unfair for the fortress player. That's why it would have to be restricted to fortress mode for everyone, to minimise most of the inconsistencies like that. Perhaps when a player logs off their fort, time would continue as normal on the server as if the fort gets retired whenever they leave.
What could make multiplayer like this extremely engaging would be how sieges against two player fortresses would work. I've seen the mod which allows for two players to work on the same fortress at the same time and I think that same idea could work incredibly well for a player vs. player siege. The two players would have to be on at the same time of course, and if one decides to invade the other they would be able to control their own dwarves on the other players fortress, attacking their dwarves, dig into their fortress, destroy structures, attempt to flood the fortress, steal goods and artifacts, and any other dastardly ideas they can come up with while they are on the other players play field.
...Of course I have no idea how any of this would actually work, so I guess I'm only asking if any of this is actually possible with the idea of multiple people playing on the same world file. At least having it be fortress mode only seems feasible to me, but really I don't know how difficult something like this would be to set up. I just had this idea and thought I might as well make a topic about it to see what others think.