The PvPvE gameplay of "Aion" revolves around battles within the Abyss and Balaurea (PvP zones). Within these zones are fortresses which can be controlled by individual Legions (the "Aion" equivalent of Guilds). Battle to control these castles involves combat against players of the opposing faction and computer controlled NPCs at the same time, using siege weapons obtained from PvE raid content. Legions in control of a castle are entitled to funding from taxes and players within the faction get specials from NPCs and discounts for travel and vendor items. The game currently does not allow factions to fight against those of their own race, except for casual duels or in the Arena, or Panesterra.