Objects in orbit - satellites and fleets - may collide with each other. In the event of a collision, both objects take damage equal to the strength of the weaker object. The object with a lower strength is therefore destroyed.

For satellites, the strength is determined by structure. When damage is received, the structure of the satellite is reduced. If a satellite is destroyed, debris is formed according to the rules described in Destruction.

For fleets, the strength is determined by the total base armor of all units. When damage is received, the fleet is partially or completely destroyed, leaving debris according to battle rules. The unit type is selected randomly, if the armor of all units of this type is insufficient to cover the damage, they are all destroyed, and a new unit type is selected to cover the remaining damage. In case when the remaining damage is less than one unit's armor, there is a chance to destroy a unit with probability equal to [damage]/[armor] (if that probability is not less than 0.01).

A collision is possible when a new satellite appears in medium orbit (e.g. teleportation, jumping entity or dunkleosteus, the appearance of a new moon as a result of battle), as well as when satellites move in local_coords. If collision are turned off for the object, in case of moving dangerously close to another object it will stop at a distance equal to the radius of the object with which the dangerous approach occurs, multiplied by 1.8.

Collisions are covered by newbie protection and vacation mode.
The player’s capital is protected from collisions.