The weapons used in the computer game Deus Ex can be divided into 5 separate categories: Pistols, Rifles, Heavy weaponry, Low-Tech (melee) weapons and Demolition weapons. Throughout the game, the player can individually upgrade skill levels for each category of weapon, making that category more effective, in terms of accuracy, range or damage. Modification kits can also be found and purchased throughout the game to enhance certain attributes of guns.
All ranged weaponry are effectively fully-automatic, since they operate non-stop as long as the attack button is held down and there is ammunition available within the magazine.
It is also worth noting that in Deus Ex, spraying fire extinguishers can be used to the same effect as the pepper gun, and dropping or throwing significantly heavy items at enemies can also be used to cause damage.
The game includes four pistols.
Pistol is the first weapon the player may handle in the game, using 10 mm Auto rounds and having a six round box magazine.
Stealth Pistol is an automatic pistol with integral suppressor for applications where stealth is desirable. While each shot deals less damage, it has better rate of fire and holding capacity of 10 rounds.
Mini-Crossbow is a small forearm-mounted crossbow designed with tactical stealth in mind. The weapon can fire three types of darts: Regular, tranquilizer or flare. The tranquilizer darts induce unconsciousness, while the flare darts generate light. It is one of few weapons that may be fired underwater.
PS20, designed to be a next-generation pistol-sized plasma weapon, is a tiny single-use weapon, akin to a derringer in proportions, capable of firing a single powerful long-range plasma blast.
Assault Rifle: This 30-round weapon has a fast rate of fire and reasonable accuracy, offset by significant recoil. It fires the potent 7.62 × 51 mm NATO round, can launch 20 mm HE grenades, and is commonly used by many Deus Ex NPCs and troops. The weapon's full designation is ZHL-U1953, shown on both the butt of the rifle and wall-mounted blueprints.
Sawed-off Shotgun: This small pump-action 12-gauge shotgun can accept both buckshot and armor-piercing sabot-type shells. It has a long reload time and its tube magazine holds only four shells.
Assault Shotgun: A relatively-compact fully-automatic shotgun that holds shells in cylindrical rotating chambers, like a revolver. This weapon is capable of clearing entire rooms with ease, if one can compensate for the immense recoil.
Sniper Rifle: A scoped sniper rifle chambered for the combat-proven .30-06 Springfield round. The in-game text boasts accuracy and precision better than 1 MOA under optimal conditions, a claim that seems quite plausible if one assumes full upgrades i.e. match grade.
GEP (Guided Explosive Projectile) Gun: The GEP Gun is a reloadable rocket launcher which utilizes laser guidance for target lock. The munitions themselves are gyroscopically-stabilized, fire-and-forget rockets with limited guidance systems. Warheads come in a choice of either regular explosive or white phosphorus (also known as 'Willie Pete' or simply 'WP'). The GEP gun fires very slowly.
Flamethrower: The flamethrower mounts onto the arm and feeds from a double-walled high-pressure napalm canister attached directly underneath. Enemies that are set alight will run about and occasionally set fire to nearby objects before expiring, though the flame can be put out with a fire extinguisher or water.
Plasma Rifle: A copy of the Plasma rifle used in Darkman, this experimental weapon works by superheating magnetically-doped plastic slugs into a lethal plasma state, which is then projected out using a linear magnetic array. The plasma rifle can be fired very rapidly.
LAW: The Lightweight Anti-Tank Weapon is a powerful single-use rocket launcher. Great care must be taken when aiming over large distances, as the rocket has no onboard guidance system to effect course corrections. It also takes up considerable room in the inventory, and thus suffers in its usefulness.
Crowbar: A simple red crowbar. Used primarily for opening crates, it also is useful in melee combat.
Baton: A telescopic baton that will render enemies unconscious instead of killing them. This weapon bears a distinct similarity with a slightly more lethal weapon (called a "Cobra") which is described in the classic cyberpunk novel Neuromancer; a narrative which Deus Ex frequently references.
Combat Knife: The combat knife does slightly less damage than the crowbar, but requires less inventory space.
Riot Prod: A rechargeable electroshock gun. Performs the same functions as the baton, but can also temporarily stun enemies.
Sword: A fairly-large Chinese sword. This weapon is primarily used by the Triads in Hong Kong.
Throwing Knives: These are designed to be used in knife throwing and cannot be used in the normal melee style.
Pepper Spray: This non-lethal weapon fires a cloud that causes severe irritation to the subject, forcing the person to deal with it in lieu of any other concerns at the moment. The pepper spray may be used to disrupt some laser beams by spraying into the beam. This is the 'cheapest' way around security aside from avoiding the beams manually.
Dragon's Tooth Sword: Also known as the 'Nano Sword' or 'Non-Eutactic Blade (NEB)'. This is not a sword in the traditional sense, as the blade is dynamically-forged on command by nanomachines in the sword assembly, and is likewise disassembled when not in use. The blade itself is non-eutactic and made of pure nanomechanical machines. It was developed by the VersaLife corporation's Hong Kong branch, who discovered a way to mix nanotechnology and traditional metals. They inserted iron rods into the carbon framework of the nanites (electromagnetically manipulated microscopic scanners, cleaners, and hammers) which continuously move over the surface of the blade, rendering it incredibly sharp and effectively unbreakable.
The Dragon's Tooth Sword has a golden handle with a button for activating the blade. The blade itself glows blue and is almost translucent giving the whole sword the look similar to that of a lightsaber from Star Wars. Oddly enough, although the blade is created on demand the Dragon's Tooth still requires as much inventory space as a regular sword.
With high levels of melee combat skill, the player can use the blade to destroy weaker robots. With the combat strength enhancement, the player can use the blade to batter down most doors and destroy military robots.
After it was stolen by the Red Arrow Triad it was renamed "The Dragon's Tooth Sword", most likely by Yuen Kong (the former Dragon Head of the Red Arrow Triad). Yuen Kwan was later tortured and killed by Maggie Chow. Later, J.C. Denton recovered the Dragon's Tooth Sword from Maggie Chow and the Majestic-12 soldiers guarding it, which was the first step to peace between the triads.
In Invisible War, the sword can be found in the recreated Chow apartment in JC's Sanctuary in Antarctica (along with other locales visited in the first game which are created from JC's memories). However, it has been changed to the shape of a katana, as the graphics of the other sword in Invisible War, the Energy Blade (a plasma-electrically enhanced katana), are used.
All of these weapons can be attached to a surface as a proximity mine or thrown as a grenade.
LAM: The Lightweight Attack Munition is a stock-standard High-Explosive grenade.
Gas Grenade: When the gas grenade bursts it emits a large amount of military-grade CS gas. This temporarily incapacitates nearby individuals except the protagonist, who instead receives damage as long as he is in the cloud.
EMP Grenade: An Electromagnetic Pulse Grenade disables electronic equipment and bots within its blast radius. It should also be noted that EMP grenades can also reduce the protagonist's bioelectric energy reserves.
Scramble Grenade: The scramble grenade interferes with a bot's normal operation, causing it to temporarily treat the player as an ally and immediately engaging all of the player's enemies that it can locate.
All of the above are dual-use, in that they can either be thrown at a target or attached to many flat surfaces, claymore-style, at which point a proximity sensor is activated. Mines deployed in this fashion by enemies can be disabled by the protagonist, the amount of time for this is governed by the player character's demolition skill.
Weapon mods cannot be added to one-shot weapons or melee weapons.
Accuracy: When applied to a gun, this weapon modification increases its accuracy. It is particularly useful on sniper rifles, the precision of which is usually insufficient. It cannot be applied to shotguns, the flamethrower, or the GEP gun.
Clip: This modification increases the ammunition capacity of the weapon it is applied to. It cannot be added to the mini-crossbow, the GEP gun, or the flamethrower.
Laser: Attaches a laser sight to a given weapon, which eliminates shot-groupings of any sort and instead cause all shots to hit the location of the laser dot. NPCs in the game do not notice the laser beam. It cannot be added to the GEP gun, flamethrower, or shotguns.
Range: A modification to increase the accurate range of a weapon. It cannot be added to shotguns.
Recoil: Reduces the recoil of the weapon. It cannot be added to the GEP gun, flamethrower, or mini-crossbow.
Reload: This modification reduces the time it takes the player to reload.
Scope: Adds a scope to a weapon that does not already have one. Shotguns and the flamethrower cannot be given a scope.
Silencer: Renders a weapon harder to hear, and subsequently locate, by the enemy. The stealth pistol and mini-crossbow are already quiet and hence do not need a silencer. Shotguns, the flamethrower, and the GEP gun cannot be silenced.