|Companies throughout Aeternum can declare War on each other. During a War, the Companies involved can attack each other without the usual Criminal penalties. Wars take place over a set amount of time, and have a Pre-War phase to allow defenders to prepare.
Each Company has the ability to set a Siege Window from the Company screen (default: [G]). While defending, the defending Company's Territory Protection can be ignored by attackers during this window. This means that their claim can be taken during this time, even if they've paid for protection. Companies should make sure that their Siege Window is set to a time that is easy for their members to participate, maximizing their chances of repelling attacks during this time of vulnerability.
For more detailed information about Territories and War, there is a chapter of the Systems Guide dedicated to it.