The main purpose of CTS games is to build a town center on a specific settlement to win.
CTS 2vs2 A - Players 1 and 2 are on a team, and players 3 and 4 are on a team. The purpose of this game is to build a town center on the opposing two settlements. Remember: the first two players to join a game (1st player = host) are the first 2 players. The 3rd to join is the third player... Remember this or your game will be messed up!!
CTS 4vs1 - Players 1-4 are the "attackers" and the 5th player is the "Defender" the defender must do all he can to protect the setlement or he loses. Players 1-4 are NOT on a team unless you want them to be.
Anal Palace - actually a form of CTS. 4 players, set on teams to your liking, will have to destroy 4 palaces in the center called the Anal Palace. After destroying the Anal Palace, the first player to conquer the two settlements wins.