Only one unit at a time may occupy an arsenal, fortress, mountain pass, or
Fortresses are not allied with a faction and can be occupied by any unit from
either side. Fortresses do not propagate communication and cannot be
An arsenal is destroyed if it is occupied by the enemy. Only empty
arsenals can be occupied. The destruction of an enemy's arsenal counts
as an attack, and no other attack may be deployed that turn.
Note: Relay units have no offensive power and thus cannot destroy an arsenal.
Cavalry can not charge against a fortress or mountain pass; any cavalry
currently occupying a fortress can not participate in a charge (although
charging while in a pass is allowed).