Watchtowers which have weapons, i.e. ‣ and ‣, can attack enemy watchtowers that are within range. If multiple enemy watchtowers are within range then you can choose which one to target on the main watchtower panel. Once a watchtower can begin attacking resources will automatically be requested.
Damage done by weapons can be increased by researching ‣, ‣ (for ‣) and ‣, ‣ for ‣.
Once a watchtower takes damage, the repair process is automatically initiated. Relevant resources (see data sheet below) will be requested and once they arrive the repairbot will start work. If a watchtower has multiple resources for repairs then the resources have to alternate, it cannot keep repairing with just one of the resource types.
Repair speeds can be boosting by researching the technologies ‣, ‣, ‣ whilst damage to a building can be mitigated by researching ‣, ‣, ‣.
If a watchtower's hit points go below zero then that watchtower is abandoned by its bots and is captured by the attacking player with a small territory radius. The watchtower goes into a 'collapsing' state giving that player a certain amount of time to repair the watchtower otherwise it will fully collapse, the building will be destroyed and the territory gain lost. Once the watchtower is fully repaired a guardbot can occupy it and it will change to its normal state, and can now attack as well as be attacked.