Battle Square is a game-mode which is a replacement for Coliseum. Unlike other game modes, battle square is a one on one with a real player in real-time.
As Coliseum were, players choose several different heroes (which vary depending on your rank) and battle against another player in real-time. Players can use different "decrees" which give them an advantage and each have their own special attribute. Mercenaries are used, but not the regular ones as the ones that are used when heroes are deployed, but new mercenaries that are only used in Battle Square.
In order to win in Battle Square, players must destroy the opponents Bastion. Usually, this involves destroying the other buildings (Tower, Army Camp/Mercenary Camp) and reach to the Bastion.
The Bastion itself can be used as a defensive building and can reserve heroes as long as you upgrade it.
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