Cooperative play also took the form of larger player-created clans called Supergroups, reminiscent of comic book groups such as the Justice League, the Avengers, or the Brotherhood of Mutants. Players part of Supergroups could team up together or convene in Bases (introduced with "City of Villains"). Bases were used for social meeting or housing special items used in crafting Inventions, serving as a collective item vault, or to recover after losing all Health in the overworld. Supergroups in turn could form Coalitions with each other for increased collaborations. Coalitions were generally formed for the raids featured in the game.