The PC game FTL: Faster Than Light has roughly half a dozen different types of weapons. Each weapon offers different advantages and disadvantages. Ion weapons differ greatly from all other weapons in the game because they can’t deal hull damage. Instead they deal ion damage which drains energy from a system and prevents it from regaining energy for five seconds per damage dealt. Furthermore, ion damage stacks and reset the timer when a system is hit that is already experiencing ion damage. Technically these weapons are blocked by shields but this just results in the ion damage going to the shield system. The following guide to ion weapons in FTL: Faster Than Light will help you decide which of these weapons are best for your needs.
Ion Blast (1 Damage / 1 Power) – The Ion Blast is not particularly exceptional because it has an 8 second cooldown rate. That means it fires too slowly to winnow down a system unless paired with at least one more ion weapon. If you have nothing better it is helpful for getting through a single layer of a shield, but it isn’t a great bargain.
Ion Blast Mark II (1 Damage / 3 Power) – This version of the weapon fires every 4 seconds, which means it is fast enough to strip a shield, assuming it doesn’t miss. The problem is accuracy and power consumption. It is pretty useful against shields with only one or two bubbles, but is unlikely to hit consistently enough for bigger shields.
Heavy Ion (2 Damage / 2 Power) – The Heavy Ion has the same problem as the Iron Blast. With a cooldown rate of 13 seconds, it just isn’t fast enough to keep a shield disabled. It is better used to disable another system after you strip shields some other way. With the right equipment and a crew member who has mastered the weapons control system, you can get the fire rate to be fast enough to strip shields, but this takes a lot of work and luck and even then it is only moderately good against 3 bubble shields.
Ion Charger (1 Damage (x1, x2, or x3) / 2 Power) – This weapon gains one charge every 6 seconds, up to a total of three charges. When fired, it depletes all charges and makes one shot per charge depleted. Like almost every other ion weapon, it needs to be paired to actually keep a system constantly depleted. If you use this, you can hold it in reserve and then pulverize a vulnerable system.
Chain Ion (1, 2, 3, or 4 Damage / 3 Power) – The 14 second cooldown of this weapon is nasty, but if the battle lasts at least 30 seconds, you have a weapon that can keep any system in the game on constant lockdown. Use it to disrupt shields and keep them out of commission and you can then pulverize the rest of the ship with more powerful weapons. This is particularly good when paired with a beam weapon because the beam weapon can tear up the ship while the Chain Ion prevents shields from ever powering.
Ion Stunner (1 Damage / 1 Power) – Effectively, the Ion Stunner is the same as the Ion Blast except with a slightly longer cooldown time and the ability to stun any enemies in the room with the system. To really make this effective you want to have your sensors at level 2 or higher. Pair it with either a good teleportation team or weapons that deal fire damage and you can easily depopulate a ship in no time.