Orbital combat occurs when a ship tries to enter the orbit of an enemy planet that has planetary defense. If multiple ships try to enter an enemy orbit the aggressiveness of the ships determines the order. If the most aggressive ship gets destroyed by the planetary defense the next ship in line enters the battle. After the planetary defense has been breached all other ships can enter the orbit freely, so it is advisable to always send the strongest ship first to breach an orbit.
Orbital combat is similar to Space combat but the planetary defense can only use energy weapons and launch interceptors out of hangars - it does not have projectile weapons. It also does not receive damage by combat, it gets depleted. Ship weapons always deal their full damage to planetary defense which means the energy and projectile weapons are more potent against planetary defense than hangars.
|Planetary defense count of planet + Planetary defense count of starbase + 100
|Energy weapon techlevel
|Square root (planetary defense count / 2)
|Energy weapon count
|Square root (planetary defense count / 3)
|Square root (planetary defense count) (+ 5 if starbase present)
If the planetary defense is breached all remaining ships can enter the orbit freely, but the planetary defense is not damaged! In the next game round it is recharged again so orbital combat occurs again if the ships try to remain in orbit. To damage it ships need to use the task planetary bombardment.