Weapons

The three pieces

Every weapon in ShmupKit is assembled from three layers. Knowing which layer owns which setting is the single most useful thing to learn here — it answers most "why isn't this working" questions.

Layer	What it is	Owns
Weapon Component	A gun position on a pawn	Where it sits on the hull, which team it shoots for, which button fires it
Weapon Data	The weapon itself, as an asset	Display name, what it costs to fire, and its list of power levels
Weapon Level	One power tier, as an asset	Fire rate, projectile count, spread, sound, fire points, the visible gun

Mounts

Every pawn has a Front mount. The player pawn adds Left, Right and Rear. Select one in the Components panel to configure it.

Property	Purpose
Weapon Data	The weapon fitted here, and the only source of firing behaviour. A mount with none logs a one-off warning and stays silent.
Mount Slot	Which hardpoint this is — Front, Left, Right or Rear. Drives pickup targeting and upgrade banking.
Mount Offset	Where the gun sits on the hull, relative to the pawn. This is the ship's hardpoint, so it stays on the component rather than the weapon.
Fire Direction	Which way it shoots, in owner space. The rear mount ships as (-1, 0, 0).
Faction	Player, Enemy or Neutral. Shots pass straight through anything on the same faction — no block, no impact effect, no damage. Neutral hits everyone.
Fire Trigger	Which button fires this mount. See below.
Inherit Owner Velocity	Adds the ship's forward speed to the shot so bullets don't appear to crawl when you're flying into them. On by default.
Fire Component	Optional. Fire from a named component (a turret head) instead of the mount offset, so shots follow whatever that component is doing.

Fire Trigger

Leave this on Derive unless you need something specific. Derive follows the convention players already expect from the genre:

• Front and rear mounts fire on the main button.
• A side mount fires on the main button while its weapon is free.
• A side mount whose weapon costs energy or ammo gets its own button, because spending should be a decision.

A free side weapon answers both the main button and its own — it fires with everything else, and can still be let off alone. Because routing is driven by which buttons are currently held rather than by press and release events, letting go of one button while the other is still down does not interrupt fire.

Option	Behaviour
Derive	Work it out from the mount slot and the weapon's cost, as described above. The default.
Primary	Always the main fire button, whatever the mount or cost.
Manual Left	Its own button — middle mouse by default.
Manual Right	Its own button — right mouse by default.
Auto	Fires by itself with no input. What enemies use.

Weapon Data

The weapon asset. Create it with right-click → Miscellaneous → Data Asset → SKWeaponData.

Property	Purpose
Display Name	Shown in UI and on the weapon select screen.
Levels	The power tiers in order, weakest first. Index 0 is the base weapon; a single entry means a weapon that never upgrades.
Auto Fire	Fires by itself while equipped, no trigger needed — for auto secondaries like a missile pack. Enemies auto-fire regardless, having no trigger.
Cost Type	Free, Energy or Ammo.

Cost

Free weapons always fire.

Energy weapons drain the pawn's energy generator by Energy Per Volley. If the pawn has no energy component, energy weapons simply fire for free — the system strips out cleanly, so you can ship without one.

Ammo weapons carry their own supply, independent of any other mount:

Property	Purpose
Max Ammo	Capacity. Refilled to full whenever the weapon is equipped.
Ammo Per Volley	Spent per shot.
Ammo Refill Rate	Ammo regained per second, trickled continuously. 0 means pickups only.

Pickup grants

When a pickup hands the player this weapon, Grant Mode decides how long they keep it. This is about ownership duration — not how long a single trigger press lasts.

Mode	Behaviour
Permanent	Kept until something replaces it.
Timed	Reverts to the previous weapon after Grant Duration seconds.
Shot Count	Reverts after Grant Shots shots.

Weapon Levels

Each level is its own data asset (SKWeaponLevelData) and holds everything about how the weapon behaves at that tier. A weapon fires at min(banked level, its own top level).

Firing

Property	Default	Purpose
Projectile Class	—	The projectile Blueprint this level fires. Damage, speed and lifespan live there.
Fire Mode	Automatic	Automatic repeats while held at Fire Rate. Salvo fires one volley per press, then waits for a fresh press.
Fire Rate	10	Volleys per second while held. Automatic only.
Projectile Count	1	Projectiles per volley.
Burst Count	1	Splits one volley into a rattle of sub-volleys.
Burst Delay	0.1	Seconds between those sub-volleys.

Shape

Three independent controls that compose freely. Getting the pattern you want is almost always a matter of picking the right one rather than fighting a single setting.

Property	Range	Purpose
Arc Angle	0–360	Total angular spread, divided across the volley's projectiles.
Projectile Spacing	0+	Parallel gap between shots, independent of any angle. Needs Projectile Count above 1.
Spread Angle	0–180	Random inaccuracy applied per shot.

Arc and spacing combine into a fan that starts wide. Spacing is also how a single floating cannon puts one shot down each side of itself — you want one fire point with Projectile Count 2 and a spacing value, not two fire points, because with two the gun mesh would sit directly on top of one of the shots.

Fire Points

A level can define any number of fire points. Each is a position with its own angle. Leave the list empty to fire from the mount position itself.

Property	Purpose
Offset	Where this point sits, relative to the mount.
Angle Offset	This one point's own firing direction, measured from centre. Range −180 to 180.
Alternate Fire Points	Off: every shot fires from all points at once (dual and spread guns). On: each shot uses the next point in rotation (missile salvos alternating left and right).

Combining both expresses patterns a plain arc cannot. The classic \ || / is four fire points at −22.5, 0, 0 and +22.5, with the middle pair separated by Projectile Spacing.

The gun

The visible cannon belongs to the weapon, not the ship, so swapping weapons swaps the model on the hull automatically — and a temporary weapon takes its gun with it when it expires. Leave Gun Mesh null if the guns are painted into the ship's own mesh.

Property	Default	Purpose
Gun Mesh	—	The cannon model for this level. Beams also emit from it when set.
Gun Mesh Offset	0,0,0	Where the model sits, in owner space. Independent of the fire points, so the cannon can sit between the shots it throws.
Gun Lag	Off	The gun eases toward its anchor as the ship moves, for a trailing sway. Shots sway with it, so they keep leaving the visible barrel.
Gun Lag Speed	10	How fast it catches up. Higher is tighter, with less sway.
Spin Rate	0	Continuous rotation, for gatling barrels.

Sound

Property	Purpose
Fire Sound	Played when the weapon fires. Leave null for a silent weapon. Beam weapons use the beam class's own sound instead.
Fire Sound Mode	Per Shot for slow and medium guns where each shot reads as distinct. Loop for fast or continuous guns — one looping sound while firing, which avoids machine-gun audio spam. A Loop sound asset must itself be set to loop.
Fire Sound Pitch Variance	Per Shot only. Random pitch per shot so rapid fire doesn't hammer one identical sample.
Loop Pitch Reference	Loop only. The fire rate the loop was recorded at. Set it and the loop pitches up as the weapon's rate increases with level. 0 disables the effect.

Enemy aiming

Property	Purpose
Aimed At Player	Fire toward the player rather than along Fire Direction.
Aim Offset Angle	Lead or trail that aim by a fixed angle, −180 to 180. Useful for making an enemy miss deliberately, or for firing a spread either side of the player.

Cost overrides

A level can override the weapon's ammo capacity or energy cost, so a fully upgraded weapon can be made hungrier or given a deeper magazine without a second weapon asset. Tick Override Max Ammo or Override Energy Per Volley and set the value beneath it. Left off, the weapon asset's own figures apply.

Beams

Set Beam Class and the level becomes a beam weapon: firing maintains one continuous laser instead of spawning projectiles, and every projectile, burst and spread setting above is ignored. Damage and length are configured on the beam class itself.

Property	Purpose
Beam Class	The beam actor to maintain while firing.
Beam Duration	How long one firing lasts per trigger press — the beam's shot length. 0 keeps it on while fire is held. On an auto-firing weapon, 0 means a permanently on beam and any value above 0 gives back-to-back pulses.

Building a weapon

Where next