Why don’t you participate in the portal’s tournaments?

I would play, especially in a 3-player game. But how do I connect, and what do I need for that? What are the rules of the game, and everything else I need to know for the overnight session?

The rules are usually written in the first post of each tournament. The main thing is to read them carefully! And, of course, follow them! ;) The game version is also usually indicated there (SOD, TE, etc.).