The Particle Cannon is a new MEC Trooper-only weapon introduced in XCOM: Enemy Within.

In-Game Description[]

Applications of our heavy plasma technology permit the creation of a burst-style particle beam, capable of unprecedented focused energy output. Its heat dispersal would be highly dangerous to an unmodified soldier, but a MEC suit is capable of mounting the necessary systems

– Engineering description, XCOM: Enemy Within


The Particle Cannon becomes available for production in Engineering after completing the Heavy Plasma research.

Production costs:

Tactical Info[]

  • Only equipped by MEC Troopers.
  • Risk of catastrophic overheating precludes suppression with this weapon.


  • The Particle Cannon's Critical Damage is incorrectly listed as 15-17 in-game.
  • Visually, the weapon is unique in that it fires in two stages, hitting a target with a weaker beam before unleashing a full-power blast. The "flinch from damage" animation in Enemy Within occurs immediately and invariably upon the first hit - in this case, the first pulse - and if the shot is lethal, the death animation occurs later. But while for most weapons it looks unnatural, for the Particle Cannon it means the target jerks violently upon being hit by the precursor beam, and is then blasted away.
  • With the "Vital-Point Targeting" skill, the weapon will reliably deal 11-13 damage (16-18 critical), making it the highest-damage weapon in the game, usually outstripping the Blaster Launcher
  • With the Overdrive ability, the weapon can be fired twice per turn.  Additionally, with Advanced Fire Control and Reactive Targeting Sensors, the unit will receive a free reaction shot with no aim penalty each turn (a common occurrence, since MEC Troopers cannot take cover).   This gives the MEC Trooper the potential to do 54 ranged single-target damage in 1 round, the highest of any class in the game (except for an offensive-build Assault or "In The Zone" Sniper in very narrow circumstances).
  • The weapon's high damage seems to be balanced against a MEC Trooper's very poor Aim stat progression (75 at Colonel). However, if you get a Sniper to Colonel rank before augmenting to a MEC Trooper, the soldier will still have 105 Aim, plus an additional 10 Aim and Critical Chance when stationary (see Platform Stability). This setup makes for a highly effective hunter-killer MEC.
  • Although no particle beam weapon was in service before the alien invasion, their effects and design elements can be predicted:
    • Particle accelerators are magnetic in design, not dissimilar to a Gauss coilgun; hence a particle weapon system is likely to leverage railgun technology.
    • Anatoli Bugorski was a Soviet scientist who had the misfortune of taking the full proton blast of the U-70 synchrotron to the head; he survived the ordeal, although suffering considerable damage and a local radiation dose a thousand times the lethal level.
    • Firing charged particle beams (of protons or electrons) in an atmosphere is suicidal due to extreme effect of Bremsstrahlung radiation, while in space the charge-induced scattering is also an issue; however, neutral particles are impossible to accelerate via magnetic fields. Therefore, a charged particle blast is neutralized upon exiting the weapon, and imparts damage to the target solely through kinetic damage.
    • Finally, in July 1989 the Los Alamos National Laboratory conducted the Beam Experiment Aboard Rocket (BEAR), sending up and recovering from a suborbital trajectory a neutralized proton (hydrogen) linear accelerator canon prototype.