Overwatch is a command in Rebelstar: Tactical Command that that gives the ability for friendly troops to act during the part of the game turn where the enemy moves. Basically what this ability does is they do a guard and its effecticeness depens on the range of each game character, with their range of view with a readied attack. The enemy, like friendly troops, use a certain number of AP to accomplish tasks and when they spend more AP than the friendly unit needs to fire the gun, they will be shot at.