The PC game FTL: Faster Than Light has roughly half a dozen different types of weapons. Each weapon offers different advantages and disadvantages. Flak weapons are unique from all other weapons controlled by the weapon control system, because you can’t directly aim them at a specific room. Instead, you have a small targeting circle that you use to aim with. When you fire a flak weapon, the shots land randomly in that circle. Except for the random spray, flak weapons closely resemble lasers, because they are blocked by shields and have a chance to cause fires. The following guide to flak in FTL: Faster Than Light will help you decide which of these guns are best for your needs.
Flak Gun I (1 Damage (x3) / 2 Power) – The Flak Gun I is excellent for taking down shields or just dealing random hull damage. You shouldn’t use it to try to target systems unless the enemy ship has a number of systems in close proximity on the ship. This gun will generally deal some hull damage early in the game, though in the later portion of the game, it is best used to strip away shields in order to set up a powerful weapon like a beam or a Heavy Laser. The recharge time on this gun is only 10 seconds, which is roughly the same time as most of the best lasers in the game. This makes it particularly good at pairing with lasers.
Flak Gun II (1 Damage (x7) / 3 Power) – The Flak Gun II can potentially deal 7 damage for only 3 power if all the shots hit. This is one of the best damage to power ratios in the game and, consequently, it is one of the best weapons in the game. This weapon has a very large targeting area, which means you basically can’t assure where any of the shots will hit. You just want to center it on the enemy ship and fire. It can tear through the largest shield in the game easily and will probably still deal damage as well. It is particularly good when paired with powerful beams like the Halberd Beam or the Glaive Beam, because it has roughly the same recharge time. Use it to strip away all shielding and then target the beam on any squares that were already hit by the Flak Gun II in order to maximize system damage. This is one of the best weapon volley combinations in the game.
Adv. Flak Gun (3 Damage / 1 Power) – This gun is automatically equipped on the Shrike. It is effectively a superior version of the Flak Gun I. It has an even better power to damage ratio, a shorter recharge time, and roughly the same target area. There is no reason to ever remove this weapon from the Shrike and if you manage to get it on another ship, you should always equip it. No other weapon in the game is this effective for a cost of only 1 power. The best thing about this weapon is that you can put it on autofire and basically not worry about it. Concentrate on other weapons and just let this deal damage rapidly. If it happens to damage two systems, the cooldown on this gun is so quick that enemies will probably still be repairing when the next attack activates.