Any fleet or home fleet may fire at an opponent at the same world. Ships on orbiting fleets have twice as much firepower as I-Ships and P-Ships. Specifically, each ship on a fleet gets one shot (except for a Trader's overloaded ships), while each I-Ship or P-Ship gets only 1/2 shot (except in ambush fire). The odd shot, if any, is rounded down.

In general, it takes two shots to destroy each one of your opponent's ships, but loaded ships are destroyed in one shot. Again, the odd shot is rounded down; and this rounding happens for each firing fleet.

Combat and movement occur simultaneously. If a fleet moves away while you fire at it, it only takes half damage, odd damage rounded down. This rounding happens per targeted fleet.

You cannot simultaneously move and fire a fleet in the same turn.