There were originally four factions in BattleForge, each representing an Element from the BattleForge universe: Fire, Frost, Nature, and Shadow. Four more have been added; each a combination of two of the elements, with two more, Nature / Shadow and Fire / Frost, planned to be added in Amii Edition or future expansions.
The first expansion, Renegade Edition, introduced the Bandit faction, both as Bandit enemies and Category:Bandit Cards, and turned the existing Stonekin enemies into playable Category:Stonekin Cards as well. It also introduced the Lost Souls faction as enemies in a new playable scenario: Empire
The second expansion, Lost Souls Edition, made the Lost Souls faction playable as well. The Twilight Cursed that had existed from the beginning were made playable Category:Twilight Cards. It also introduced a game element of opposition between the Twilight forces and the Lost Souls that were behind the very creation of the Twilight Curse.
Amii Edition factions shown by its pre-release cards were only Bandit and Twilight faction; therefore, it is not yet known whether a new faction will be introduced in Amii edition.