Secondary

Secondaries are plane-specific items that grant unique active abilities while equipped. These abilities require Steam to be activated, with each type using a specific quantity. Secondaries are the only equipment type which cannot be crafted --- items of this type can only be obtained from enemies or mission rewards.

Secondaries can be sorted into several categories: Direct Damage (projectile and area-of-effect attacks), Healing (Armor-restoring effects), Multishot Support (bullet-multiplying effects), Indirect Damage (attacks using minions), Damage Reduction (effects reducing damage taken), and Anti-Bullet (bullet-removing effects).

Old Faithful: Acid Clouds
Drops a cloud of acid that enemy planes fly through.

Acid clouds, which deal damage over time to enemies, cost 25 Steam to use and can only be deployed once every 3 seconds. When deployed, they start at minimum size and grow to maximum size over the first 0.5 seconds of their lifetime.

Hog: Propeller Blasts
Hit all enemy planes within range with acid damage.

Consumes 21.6 Steam to produce a short-lived blast with a 3-unit radius which deals a single instance of heavy damage to enemies caught within it. Lasts for 1.7 seconds and can only be used once every 4 seconds.

Bandit: EMPs
EMPs consume 20 Steam to fire a piercing bullet which slowly travels over a 12-unit distance and confuses enemies it hits for a fixed amount of time, preventing them from moving, rotating or shooting bullets for the duration. Bosses and minions critical for certain boss mechanics, however, are immune to the effects of EMPs (they instead take extra Confuse damage), and confused enemies are still able to spawn minions and non-bullet projectiles.

Bullets fired by EMPs are affected by multishot.

Medic: Healing Blasts
Hovering micro-mechanics that repair damaged allies.

Healing Blasts consume Steam to grant instantaneous healing to nearby allies, even those in the middle of a death animation (getting healed while in a death animation usually brings the plane back into fighting condition if done before it explodes). Lasts for 0.5 seconds, has a 6-unit blast radius and can only be used once every 3 seconds.

Paladin: Healing Auras
Healing Auras grant improved armor self-repair over a long period to nearby allies.

The aura begins at a 0.1-unit radius and grows to a final 5-unit radius over the first 0.5 seconds of its 10-second lifetime. Once the aura ends, the Paladin must wait 3 seconds before using a Healing Aura once more.

Costs 70 Steam to use.

Multishot Support
Multishot Support Secondaries double the number of bullets shot by the Weapons and abilities of allies, but reduce fire rates to (Multi / 2) * 100% of normal for the duration; for weapons with time-based clip sizes, the fire rate reduction extends the clip size by ( (2 / Multi) - 1 ) * 100% of normal.

For example, for Multi = 1.6, fire rates are reduced to [ ( 1.6 / 2 ) * 100% = 0.8 * 100% = ] 80% of normal and time-based clip size is increased by [ ( (2 / 1.6) - 1 ) * 100% = ] 25% of normal.

Quad: Multishot Blasts
Powers up nearby ally weapons.

A short-lived burst with large area of effect which instantaneously increases the number of bullets fired by ally armaments for a short time. The activation cost is 40 Steam, the blast lasts for 0.5 seconds and has a 5-unit radius, and Multishot Blasts can only be used once every 3 seconds.

Assault, Duster: Multishot Clouds
Powers up ally weapons.

A long-lived cloud with small area of effect which increases the number of bullets fired by ally armaments for a short time whenever they fly through the cloud. Though cloud deployment costs 70 Steam and has a 3-second cooldown associated with it, the cloud increases its radius from 0.2 to 3 over the first 2 seconds of its lifetime and stays around for a while, allowing allies to benefit from it multiple times.

Raptor: Mine Layers
Mine layers, usable only once each second, produce floating explosives that detonate when an enemy comes within their detection range. Blast radius and damage done by the deployed mine scale with tier, but the 25 Steam cost does not.

Engineer: Turrets
A boxy contraption that once defended France against the Endless Plague of zombie lemmings.

Consumes 30 Steam to deploy stationary turrets, classified as spawns by Pilot Skills, with 15 Armor and a turn rate of 40 degrees per second that rotate toward and shoot at nearby enemies at a rate of 1.5 shots/sec.

Turrets will lock onto and fire at enemies within a 40-degree arc which are at most 10 units away, but their bullets can only travel 7 units before they despawn. Deploying a turret incurs a 1-second cooldown on the ability and sets the turret's initial orientation to that of the Engineer.

Turrets cannot be damaged by enemy attacks; however, they will rapidly lose Armor whenever the Engineer strays too far and slowly regenerate Armor after the Engineer comes back within range. Turrets that do not die from neglect will unavoidably expire after a set duration.

Shieldmaiden: Auras of Defense
Auras of Defense grant temporary protective shielding to allies in range, reducing damage taken by one third. Begins at a 0.1-unit radius and grows to a 5-unit radius over the first 0.5 seconds of its lifetime. Costs 70 Steam to use and incurs a 13-second cooldown between uses.

Dagger Knight: Shield Blasts
"Grants a temporary shield to itself and nearby allies."Shield Blasts grant protective shields to the Dagger Knight and nearby allies which greatly reduce damage taken for 4 seconds. Blast radius and damage reduction scale with Shield Blast tier.

Additionally, the Dagger Knight is empowered for 4 seconds whenever they use a Shield Blast, increasing gun damage by +20% and reducing weapon reload times by 75%; in exchange, weapon range is reduced by 75% for the duration.

Costs 50 Steam to use.

Merlin: Wipers
Wipers, classified as vortexes by Pilot Skills, grant passive Steam regeneration to their wielders and can be activated to delete projectiles around the Merlin using Steam. Wiper usage is restricted to once every 0.2 seconds.

Siege Tank: Flak Cannons
"Destroys incoming enemy bullets."Flak Cannons passively grant +1 to Steam Recharge and can be activated to discharge several bullet-deleting explosions in the direction of aim. Flak Cannons, which have a 0.2-second delay between consecutive discharges and spread out their explosions about a point 2.6 units away from the Siege Tank's center, cannot be used while Siege is active.