Colladv was an collaborative online textual game I made in 2014. It's one of the projects I was quite happy about.

The main interface was like a standard textual adventure game where you read descriptions of rooms and type sentences such as "open door" to interact.

room 01

But there was twist to it : each time a player typed an unknown commmand line, the game kept track of it.
If that command was the top unknown command for a given room (if many players had asked to do the same thing before) then the player could choose the consequences of the action by creating a new room or returning to a previous visited room.

choice 01

example

The game started with only one room but due to an unexpected popularity rush, it expanded quickly and was filled by hundreds of rooms within a few hours (until my server crashed).

Here is a graph of possible interactions designed by players after a few hours :

graph 1

I didn't include any item or player-wise variables, just descriptions of rooms. It seemed to be enough for players to have fun. I would still like to try a mud-like approach someday.

I made two versions of this game. The second version was slightly more stable and featured pictures but I decided to remove them at some point.

Due to technical reasons the game is buggy now but can still be played here Colladv.