[PvK]

Well, Combat Sensors are the answer. If FE is Federation & Empire, which was based on Star Fleet Battles, then I can guess that yes, it works almost the same way, except that in SE4, Combat Sensors give a bonus to hit if they exceed enemy ECM. In SE4 in patches since er... a year or so ago, to-hit mods that don't replace each other are additive for attacker and target, so +65 to hit on a target with a -50 defensive bonus results in a net +15 to hit, which is then added to the base hit chance and the range modifier, etc. Every to-hit mod (besides multiple components of the same type) adds.

PvK