"You're Nexus Force now--fight for Imagination!"- Epsilon Starcracker
|Main Location||Nexus Tower|
|Allies||Pirates, Ninja, Nexus Force|
"Imagination is the living foundation and power of all that is possible and impossible in the universe." - Doctor Overbuild
Assembly is mainly composed of builders who believe in the power of imagination and creativity. They are led by Doctor Overbuild, one of the original discoverers of the Nexus. They use amazing creations and summoned creatures to defeat the Maelstrom. The faction emblem is an orange Penrose triangle, and the specialties consist of the Engineer, the Summoner, and the Inventor.
"Exploration is truly the essence of imagination." - Hael Storm
The Venture League (commonly known as Venture) is based on exploration and puzzle-solving. Its members consist of brave trailblazers and adventuers, going where no minifig has gone before. The faction emblem is a skull set in the middle of a green compass rose, and the faction is led by space pirate Hael Storm. The specialties include the Daredevil, the Buccaneer, and the Adventurer.
"Believe in your strength without abusing it. Acknowledge strength in others without fearing it." - Duke Exeter
The Sentinels are made of brave warriors, fighting to protect others from the Maelstrom. Duke Exeter, a famous warrior knight, heads this group of fearless heroes. The faction symbol is a blue falcon on a yellow shield. The faction specialties include the Knight, the Samurai, and the Space Ranger.
Members of the Paradox faction focus on turning the power of the Maelstrom against itself. The plaque at the end of Mission 19 states that they are "highly secretive and viewed with suspicion by the other factions", but that they are "always trusted to do the right thing." They are led by Vanda Darkflame, a ninja and former apprentice of Baron Typhonus, and their symbol is a tiger eye inside a hurricane. The specialty kits are the Space Marauder, the Sorcerer, and the Shinobi.
- A Mythran can join all four Factions, raise rank at will (even up to rank 4), and obtain all Faction gear and specialty kits through means of a special Macro code.
- The additional third Faction specialty kits were once available during Alpha and Early Beta before they were pulled later on for not working correctly. However, as of the August 9th patch, they are once more available.
- After the May 3rd patch, faction cars and rockets became available for purchase from the Faction vendors at Nexus Tower.
- Early on in the development of LEGO Universe, the four factions were known as Assembly, Thunder, Vanguard, and Adventure.
- There are four different sub factions. They are Non-Faction Specialties.