Abyssus Weapon & Fire-Mode Unlocks
Find every weapon location and all 54 primary and secondary fire-mode requirements, including Harpoon Gun, Combat Bow, Plasma Launcher and challenge rewards.
Where do weapon mods go?
Pick your unlocked Primary and Secondary fire modes at the Lobby Workbench. Each weapon has three of each. Ancient Forge upgrades are separate choices obtained during an expedition.
Timed side rooms use the conditions below; collect the weapon before taking the area’s exit portal.
All nine weapon locations
Engine Rifle
Collect it beside the fallen Brinehunter in the tutorial.
Shotgun
Defeat Elite Overseer, then jump to the tent-covered ledge beside the exit portal and collect it from the table.
Tesla Gun
Defeat Elite Berserker and collect it from the table beside the exit portal.
Brine Revolver
Look on the barrel near the Workbench in the Lobby and pick it up.
Disc Thrower
After General Kri’su, drop into the pit before taking the exit portal. Destroy the red pylons hidden in the pipes to open the rear temple door; follow the tunnel to the weapon.
Combat Bow
Defeat Elite Catalyst in under 45 seconds. Turn right when leaving the arena and follow the side corridor to the pedestal. A wall blocks the route if the timer is missed.
Plasma Launcher
Reach the Royal Abyss within 45 minutes. Leave the spawn building, turn right and jump across the dark chasm to the weapon room. The passage seals after the time limit.
Fish Deity
Defeat each of the three Royal Abyss heralds at least once. Return to the Lobby waterfall, enter the corridor behind it and interact with the hidden wall. Collect the fish from the fountain once all three statues activate.
Harpoon Gun
Defeat The Golemancer for a second time. Before using the exit portal, take the passage revealed by the crumbling wall and collect the gun beside the fallen Brinehunter.
All 54 fire modes and their requirements
18 default modes become available with their weapon. The remaining 36 come from challenges. Requirements name the action needed, so you can plan an unlock run before choosing a build that depends on it.
| Weapon / slot | Fire mode | Challenge | Requirement |
|---|---|---|---|
| Engine Rifle primary | Automatic Fire | Default | Available when this weapon is unlocked. |
| Engine Rifle primary | Burst Fire | Gun Meets Crown | Complete an Expedition with the Engine Rifle. |
| Engine Rifle primary | Gatling Fire | Eco Warfare | Kill 10 enemies without reloading with the Engine Rifle. |
| Engine Rifle secondary | Engine Rev | Default | Available when this weapon is unlocked. |
| Engine Rifle secondary | Split Shot | Drumfire | Kill 30 enemies with explosions while using the Engine Rifle. |
| Engine Rifle secondary | Concentrated Shot | Deadline | Get 3 kills while the Engine Rifle is overheated. |
| Shotgun primary | Semi-automatic | Default | Available when this weapon is unlocked. |
| Shotgun primary | Full-automatic | Triple Kill! | Get a triple kill with the shotgun. |
| Shotgun primary | Superheavy Slug | Up Close & Personal | Complete an Expedition with the Shotgun. |
| Shotgun secondary | Buckshot | Default | Available when this weapon is unlocked. |
| Shotgun secondary | Unload | Ricky's Creed | Kill 30 enemies with melee attacks while using the Shotgun. |
| Shotgun secondary | Pressure Shot | Boomstick | Travel a total distance of 1000 meters with the buckshot's knockback. |
| Tesla Gun primary | Electrical Beam | Default | Available when this weapon is unlocked. |
| Tesla Gun primary | Charge Beam | Wildfire | Apply 100 damage over time effects with the Tesla Gun. |
| Tesla Gun primary | Unstable Coil | Caged No More | Complete an Expedition with the Tesla Gun. |
| Tesla Gun secondary | Spark Orb | Default | Available when this weapon is unlocked. |
| Tesla Gun secondary | Charge Orb | Battery | Hit enemies 100 times with a single spark orb. |
| Tesla Gun secondary | Magnetic Storm | Electrifying! | Deal damage to 6 enemies at the same time while using the Tesla Gun. |
| Brine Revolver primary | Semi-automatic | Default | Available when this weapon is unlocked. |
| Brine Revolver primary | Burst Fire | High Noon | Kill 5 enemies without leaving scoped mode with the Brine Revolver. |
| Brine Revolver primary | Large Caliber | Good, Bad and Ugly | Complete an Expedition with the Brine Revolver. |
| Brine Revolver secondary | Steady Scope | Default | Available when this weapon is unlocked. |
| Brine Revolver secondary | Quick Scope | Town Ain't Big Enough | Kill 3 Bosses with a Weakspot hit while scoped with the Brine Revolver. |
| Brine Revolver secondary | Charge Scope | Sharpshooter | Deal 500 overkill damage in a single shot with the Brine Revolver. |
| Disc Thrower primary | Automatic | Default | Available when this weapon is unlocked. |
| Disc Thrower primary | Fan Fire | Disco Fever! | Complete an Expedition with the Disc Thrower. |
| Disc Thrower primary | Dynamo | Inferno | Hit 5 enemies with a single flame burst while using the Disc Thrower. |
| Disc Thrower secondary | Inferno Discs | Default | Available when this weapon is unlocked. |
| Disc Thrower secondary | Electron Conductors | Dr. Discstein | Kill 50 enemies with Lightning while having the Disc Thrower equipped. |
| Disc Thrower secondary | Search and Destroy | Flying Power Disc | Hit enemies 50 times within 5 seconds with the Disc Thrower. |
| Combat Bow primary | Precision Shot | Default | Available when this weapon is unlocked. |
| Combat Bow primary | Pierce | Robin Hood | Complete an Expedition with the Combat Bow. |
| Combat Bow primary | Return Arrow | Bottomless Quiver | Have 20 arrows in a row hit a target while using the Combat Bow. |
| Combat Bow secondary | Multi-Shot | Default | Available when this weapon is unlocked. |
| Combat Bow secondary | Smart Arrow | X Marks the Spot | Hit 200 Weakspots with the Combat Bow. |
| Combat Bow secondary | Exploding Arrow | Three for One | Kill 3 enemies with a single pierce arrow while using the Combat Bow. |
| Plasma Launcher primary | Semi-automatic | Default | Available when this weapon is unlocked. |
| Plasma Launcher primary | Flak Cannon | Kaboom! | Kill 30 enemies with a Weakspot hit with the Plasma Launcher. |
| Plasma Launcher primary | Seekers | Boom! | Hit 3 enemies with a single Plasma Launcher explosion. |
| Plasma Launcher secondary | Disintegration Beam | Default | Available when this weapon is unlocked. |
| Plasma Launcher secondary | Void Infusion | Shot, Chaser | Kill 3 enemies at the same time with Seeker projectiles. |
| Plasma Launcher secondary | Adhesive Compound | Plasmaster | Complete an Expedition with the Plasma Launcher. |
| Fish Deity primary | Rapid Goo | Default | Available when this weapon is unlocked. |
| Fish Deity primary | Fish Spit | Free Throw | Kill 5 enemies 40 meters away with Fish Deity projectiles. |
| Fish Deity primary | Hazardous Goo | Open Wide | Hit 5 enemies with a single stab while using the Fish Deity. |
| Fish Deity secondary | Piercing Stab | Default | Available when this weapon is unlocked. |
| Fish Deity secondary | Wide Stab | Go Fish! | Complete an Expedition with the Fish Deity. |
| Fish Deity secondary | Chainsaw | Hooked | Kill an Elite in less than 20 seconds while using the Fish Deity. |
| Harpoon Gun primary | Piercing Harpoons | Default | Available when this weapon is unlocked. |
| Harpoon Gun primary | Ricocheting Harpoons | Fishing Season | Gain a fire rate of 200% while using the Harpoon Gun. |
| Harpoon Gun primary | Pinning Harpoons | Slaying a White Whale | Complete an expedition with the Harpoon Gun. |
| Harpoon Gun secondary | Barbed Harpoons | Default | Available when this weapon is unlocked. |
| Harpoon Gun secondary | Binding Harpoons | C-C-C-COMBO | Spend 8 Combo Points within 2 seconds. |
| Harpoon Gun secondary | Brine-Powered Harpoons | Hook, Line and Skewer | Gain a weakspot hit on 3 enemies by piercing them with a single harpoon. |
Corrections to common unlock lists
Charge Beam is the reward for Wildfire; Battery rewards Charge Orb. Dynamo is unlocked by Inferno, not a challenge named Dynamo. These mappings use the Logbook challenge reward rows to resolve conflicting weapon-page labels.
Sources: individual location pages linked above, challenge conditions and rewards, and official Update 1.3 roster of nine weapons and 54 modes.