There are currently 3 Factions that has different modifiers (such as Increased damage, RoF, Impact etc.). The factions are:
Keep in mind, once the five player limit on the factions have been reached, the icon slightly darkens and you can not select the icon. Once a player from the filled faction leaves the server, the faction will be available again.
The Illumi faction fights for freedom. Illumi guns have very low recoil and focus on speed and accuracy. Their icon resembles a green arrow facing the right with a green background. When the Illumi capture a planet, the planet's icon on the map shows up green.
The Derept faction fights for power. Derept guns have increased aiming accuracy and walkspeed, and they focus on speed and power. Their icon resembles an orange 'M' structure on a red circle, with a red background. When a planet is captured by the Derept, the planet's icon on the map shows up red.
The Guard faction fights for law and order. Guard guns deal more critical damage, and they focus on accuracy and power. Their icon resembles a blue tower like structure on a blue background. When a planet is captured by the Guard faction, the planet's icon on the map shows up as blue.