Resistance values are essentially a filter that determines how much incoming damage actually effects your ship. The higher resistance to a damage type (thermal, EM, Kinetic) your ship has, the less that damage type will hurt you. There is both hull and shield resistance values, and they are separate from each other.
- If a ship has 0 shield resistance to EM damage, then this means that full damage will be done to the shield. (100% incoming damage is inflicted on the shield)
- If a ship has 50 shield resistance to EM damage, then this means that incoming EM damage to the shield will be reduced (incoming Thermal/Kinetic damage will not, unless those resistance values are high as well)
- If a ship as -5 shield resistance to EM damage, then this means that incoming EM damage to the shield is increased (extra damage)
Having higher resistance is just as good as having higher health. Depending on the enemies you are fighting (Hint: Aliens use mostly EM weapons), you can tailor your ship to be better suited to a specific enemy, or you can balance the resistance values to make your ship good all-round. Obviously, more health (i.e. hull/shield volume) is good too, but balancing this with resistance values makes for a longer lasting ship... high resistance does little good when you have only 1000 hull points, but 10,000 hull points goes by fast if you take crippling damage every hit!
You modify hull/shield resistance values (and hull/shield volume) of your ship by changing/upgrading passive modules: many give or take certain resistance values. Some active modules, like hull and shield buffs from a Command fighter, can add on additional resistance as long as you are under the module's effect, making you harder to kill!
How resistance values work
Work in Progress