If you are ready, you may attempt to rule a player by clicking the “Rule” button. If you successfully defeat the player, then you turn their base into your colony and they will pay you some crystals when gathering crystals. Only those who are in the same faction with you and also residing in the same galaxy with you may become your colony.
Your Rank determines the maximum amount of bases you can colonize. While you are a Rookie, you can only colonize one base. A Private First Class can at most colonize 2 bases, a Corporal is able to colonize a maximum of 3 bases. Each player will only colonize 3 bases at the same time.