The Amprex rifle fires a continuous beam of high voltage electricity that arcs among nearby enemies. This weapon excels at crowd control.

The Amprex is a IconCorpusOn Corpus beam rifle that fires a continuous stream of DmgElectricitySmall64 Electricity arcs that can chain between units, making it a devastating crowd control weapon.


  • This weapon deals DmgElectricitySmall64 Electricity damage.
  • Mod TT 20px Heavy Caliber's accuracy penalty is minimal on this weapon.
  • Beam can chain up to 3 nearby enemies within 10 meters from the initial target, with each chain doing 50% of the previous chain's damage.
    • Each enemy hit by the main beam from Punch Through can generate a new set of 3 chains.
    • Enemy corpses will still allow the beam to connect to nearby enemies.

Advantages over other Primary weapons (excluding modular weapons):

  • Second highest critical chance of all continuous and automatic primaries, behind Synapse Synapse.
  • Consumes 0.5 ammo per tick of damage.
  • Normal Attack (wiki attack index 1)
    • High crit chance (32.00%)
    • High magazine (100)
    • High ammo max (700)
    • High fire rate (12.00 attacks/sec)
    • Above average crit multiplier (2.20x)

Disadvantages over other Primary weapons (excluding modular weapons):

  • Damage ramps up from 30% to 100% over 0.6 seconds when firing. After firing stops for 0.8 seconds, the damage decays back to 30% over 2 seconds.
  • Main beam has a limited range of 18 meters.
  • Chain beam has a limited range of 10 meters.
  • Normal Attack (wiki attack index 1)
    • Low reload speed (2.60 s)
    • Very low total damage (22)
    • Very low disposition (●●○○○ (0.85x))

See WARFRAME Wiki:Stat Comparison/Percentiles for more details.


The Amprex's blueprint can be researched from the Energy Lab in the dojo.

Manufacturing Requirements
📝 Edit blueprint requirements
Fieldron Fieldron
Plastids Plastids
Ferrite Ferrite
ArgonCrystal Argon Crystal
Time: 1 Day(s)
Rush: PlatinumLarge 35
MarketIcon Market Price: PlatinumLarge 225 Blueprint2 Blueprints Price:Credits50,000
Energy Lab ResearchClanAffinity643,000
FieldronSample Fieldron Sample
Plastids Plastids
NanoSpores Nano Spores
PolymerBundle Polymer Bundle
Time: 3 Day(s)
Prereq: Dera
Ghost Clan x1   Shadow Clan x3   Storm Clan x10   Mountain Clan x30   Moon Clan x100

This weapon can be sold for Credits64 7,500.


  • When fired at an enemy, the beam will chain to the closest enemy within 10 meters of the initial target. From there it will chain again, up to a maximum of 3 chains in total. A chain will do 0.5n times the main beam's damage, where n is the chain number. Any enemy caught in the width of the beam will also be damaged.
    • The damages are : 100% for the main target, 50% for the first in the chain, 25% for the 2nd, and 12.5% for the 3rd.
    • Headshotting the original target does not affect the chain damage.
    • The beam will not chain to a Nullifier through its shield should it connect with a target outside or partially enclosed by it.
    • The beam can also continue to chain to enemies even if targeting a dead enemy or an enemy who is dead but in a dying animation.
    • Additional electrical arcs are also emitted, striking randomly around the player. However, these stray arcs are purely visual in effect.
  • Compared to the Synapse Synapse, the Amprex deals more damage and it continuously arcs to other enemies, making it more effective against crowds. Use the Synapse for single targets and the Amprex for crowd control.
    • The fire rate of Amprex is the same as Synapse, and it deals slightly more damage, however it has a 2.6s reload speed, nearly double the 1.5s reload speed of the Synapse.


  • This weapon's high critical chance and damage make it ideal for critical focused builds using Mod TT 20px Point Strike and Mod TT 20px Vital Sense.
  • The Amprex's high fire rate and its low base damage make it highly ammo inefficient, consuming ammo at an alarming rate. It is recommended to use Mod TT 20px Rifle Ammo Mutation, Carrier's Mod TT 20px Ammo Case, or Mod TT 20px Rifle Scavenger to ensure a steady supply of ammo. Alternatively, bring Squad Ammo Restores to help replenish lost ammo.
  • Alloy Armor is highly resistant to electricity damage. To counteract this, consider pairing it with DmgFireSmall64 Heat or DmgToxinSmall64 Toxin damage to respectively create DmgRadiationSmall64 Radiation or DmgCorrosiveSmall64 Corrosive damage.
  • Mod TT 20px Critical Delay can be used to reduce ammo consumption, increase time between reloads, and increase damage per hit, but at a cost to the weapon's DPS.
  • Although it is preferred to mod the weapon to other damage types, base DmgElectricitySmall64 Electricity damage paired with its high status chance makes for a good stunning weapon among groups, and the added damage through electrical procs that chain to other enemies. Infested have no weakness or resistance to electrical damage, making the base electrical damage work well for that faction. Forma is often required to change the damage type to match the amount of damage done by pure electrical damage, however.
  • Using with MirageIcon272 Mirage gives you two more beams that also chain to other targets, providing much more crowd control.
  • Decreasing the accuracy of the Amprex with a mod like Heavy Caliber will not only increase the Amprex's damage but works well for large groups of enemies as it increases the spread of the weapons Fire.
  • Punch Through will cause the main beam to chain independently from each additional target hit, potentially doubling or tripling the total damage output when fired into a crowd. The chain from the target hit after the Punch Through can deal damage to the first target, and vice versa.


  • After the clan obtains the Energy Lab, it will take exactly 12 days to research this weapon.
  • The Amprex's name is a portmanteau of the words Ampere (the base unit of the International System of Units used to quantify electric current) and the word Rex, which is the Latin word for king.
    • The word ampere itself is named after a French mathematician and physicist, André-Marie Ampère, who's also considered to be one of the fathers of classical electromagnetism, most commonly known for Ampère's Circuital Law.
    • Like the FluxRifle Flux Rifle and Detron Detron, Amprex does not conform to the common Corpus weapon name scheme; two syllables ending in 'a'.
  • The weapon shares its similarities on its battery components with Tetra Tetra.
  • This is the third Primary weapon that deals purely DmgElectricitySmall64 Electricity damage, after Lanka Lanka and Synapse Synapse (since Hotfix 22.13.3 (2018-02-21) Synapse deals DmgCorrosiveSmall64 Corrosive instead).
  • This is the second clan weapon that does not need a Forma in its construction.
  • Hatches on the side of the Amprex slowly open up during firing, spreading vanes underneath. This animation is a visual indicator of the weapon's magazine capacity, with the vanes spreading out more the closer the magazine is to empty. The hatch closes upon reloading.
  • This is the first weapon in Energy Lab whose duplication costs 50,000 credits.
  • After Update 15.13 (2015-02-05), the chained beams were changed to be affected by Mod TT 20px Sinister Reach as well. As of Update 22.14 (2018-03-01), this is no longer the case.


Amprex Skins


Patch History[]

Update 32.0 (2022-09-07)

Ammo Changes

We understand the power fantasy of these weapons is very popular for some, so our first approach was to keep them powerful, but limit how often they can be used by making changes to ammo pick-up.

Ammo Pickup Overrides
The following weapons now have ammo pickup overrides, meaning they gain less from picking up ammo. This mostly applies to AoE weapons, in hopes that players will become more deliberate with their aim to make the most of their Ammo pools. The following lists the specific ammo pick up overrides per weapon category.

Primary Weapon Ammo Pick Up Overrides

60 Ammo per Pick Up:

  • Amprex

Update 22.14 (2018-03-01)

  • Fixed Beam weapons not being able to damage enemies (alive but in a ragdolled state) when being affected by certain ‘crowd control’ Abilities.
  • Damage now ramps up over 0.6 seconds and after moving off target there is a delay of 0.8 seconds before it starts to decay over 2 seconds.
  • All Beam weapons now start their Damage ramp up at 20% (instead of 10%).
  • The Multishot chance should now apply more consistently with Beam weapons.
  • Weapon Range Mods (like Sinister Reach) no longer affect the distance of chains for chainable Beam weapons (like the Amprex). Main Beam distance is still affected by them.
  • Fixed Beam weapons continuously firing when quick Meleeing.
  • Chain Range increased from 7.5m to 10m.
  • Damage reduced from 24 to 22.

Hotfix 22.13.4 (2018-02-22)

  • Increased the Beam weapon Damage ramp up time from 0.8 to 1 second.
  • Fixed Beam weapon Damage ramp up not happening per target.

Hotfix 22.13.3 (2018-02-21)

  • Perfect accuracy and high fire rate is balanced by limited range and damage ramping up from 10% to 100% over 0.8 seconds when firing and decays back to 10% over 1 second after stopping.
  • Mastery Rank increased from 5 to 10.
  • Damage increased from 7.5 to 24 .
  • Fire Rate decreased from 20 to 12 .
  • Status chance changed from 20% per sec to 22% per tick of damage.
  • Critical chance decreased from 50% to 32%.
  • Critical Damage increased from 2.0x to 2.2x.
  • Max ammo capacity increased from 540 to 700.
  • 0.5 Ammo consumption per tick of damage.
  • Aimed Zoom reduced from 2.23x to 1.4x.

Update 19.5 (2016-12-22)

  • Magazine size in Conclave reduced from 100 to 40.

Update: The Index Preview (2016-10-20)

  • The Amprex can now be used in Conclave.

Hotfix 18.8.2 (2016-04-13)

  • Decreased the rumble amount on controllers when continuously firing the Amprex.

Update 17.4 (2015-09-09)

  • Fixed some lingering visual FX from Amprex when used with Mirage’s Hall of Mirrors

Hotfix 16.5.3 (2015-05-13)

  • PBR material has been added to the Amprex!

Hotfix 16.4.1 (2015-04-23)

  • Fixed Amprex not chaining to nearby enemies.

Update 15.13 (2015-02-05)

  • Sinister Reach will now extend the Amprex’s chain lightning effect.

Hotfix 14.0.11 (2014-07-30)

  • Damage multipliers for the Amprex normalized.

Update 13.3 (2014-05-14)

  • Fixed an issue with the reload animation for the Amprex not properly coinciding with when the magazine was refilled.

Hotfix 13.1.2 (2014-04-25)

  • Improved the performance of the Amprex on low end machines.
  • Fixed the visuals on the battery component of the Amprex rifle.

Update 13.1 (2014-04-23)

  • Introduced.

See also[]

  • Synapse Synapse, the Infested equivalent of this weapon.
  • Atomos Atomos, a Grineer particle cannon with a functionally equivalent chaining beam.
  • KuvaNukor Kuva Nukor, a Kuva Lich sidearm with a functionally equivalent chaining beam.
  • TenetCycron Tenet Cycron, a Tenet weapon with a similar chaining beam.
  • Larkspur Larkspur, an Archgun with a functionally equivalent chaining beam.