When a fleet or colony is being attacked, if it is being overpowered it will send out a distress call to nearby fleets for assistance. A colony will always send a distress call at the start of a battle, however many times the colony's ground defense is smashed before friendly fleets can show up to help. Any fleets that have standing orders to answer distress calls will transfer to the battle location and support the fleet or colony that made the call.

It must be noted, however, that distress calls made by a fleet at the entrance to a system usually need to be repeated multiple times before they are answered - and they are sometimes not answered at all.