How do you play MultiPlayer on warrior cats untold tales?

Keep an eye on the Multiplayer section of the Untold Tales forum. Every once in a while - usually around holidays - Falconstar will put the server on (you can't play if Multiplayer is offline). You must download the Multiplayer version of the game (there's a link on the thread that says "online"/"offline" ), and then you will be able to play it.