Stun gun

The Buzzkill TND (Threat Negation Device) is a weapon in Deus Ex: Human Revolution.

Characteristics
The Buzzkill TND instantaneously knocks individual targets unconscious at close range. Also useful on bots and electronic devices to confuse them temporarily, the stun gun is made by Mustang Arms Ad-Tech Ltd. As both are ranged, non-lethal firearms which can only load one shot at a time, both the stun gun and its cousin the PAX-22 fill a similar niche, albeit at different ranges. The small stun gun is only useful at short-shorter medium ranges, but can affect non-human targets. With its scope, the PAX-22 is best used at sufficient range for the scope to not interfere with aim.

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The Stun Gun is the only weapon that can instantly take out any enemy in the game, human, augmented or robot and even boss enemies [This needs to be verified did not work for me on Barrett on Realistic]. Additionally no aiming is required: just flat at the torso is enough. Alerting the enemy, then awaiting them behind an obstacle will make them come one by one to be taken out.=====

After stunning them, the player has to watch the bodies to be either not found by other enemies or not revived, which can be done quickly.

Enemies that will awake by themselves (machines, bosses) need to be taken care of during their sleep (carried away into corner, obstruct view, passed by or, with bosses: heavy fire while they are down).

It should be noted that, unlike the PAX-22, the Stun Gun is NOT silent.

In-game Description
The Buzzkill Threat Negation Device (TND) is a single-shot, non-lethal firearm that uses an intense electroshock discharge to render targets unconscious. While easy to conceal, the weapon has a short range, slow firing cycle, lengthy reload time, and has no sights for aiming (although adding a reticule on the screen through the Options Menu mitigates this problem). It is primarily for use against organic targets, but is also effective in temporarily disabling security camera, turrets and bots without setting off alarms.

The stun gun is best reserved for situations where patrolling enemies must be incapacitated quickly, with or without executing takedowns; either because the distance is too far that it can compromise stealth, or energy is insufficient to perform one.

As hand-to-hand combat freezes time and renders the player temporarily invulnerable, a one-two punch of a takedown on one target, then a shot from an already drawn stun gun on another target is a quick and easy tactic for incapacitating two enemies at once, useful for pairs of enemies that are standing within close range (should the Quicksilver Reflex Booster remain locked, or the targets lack proximity for Double Takedowns), which is quite a common occurrence.

Locations

 * The stun gun can be first received from David Sarif during the first mission, by requesting a close-range nonlethal weapon.
 * One can be purchased from Seurat.
 * It can be found, along with some darts, in a locked lot in Detroit. Hacking capture level 2 is required, or there is a Pocket Secretary on the wall nearby that has the locker code.
 * Another Stun Gun can be found in the back of a red cargo truck near the entrance of FEMA Detention Center.
 * Inside the FEMA detention center, at the top of the stairs to the top level of the initial area, lift a crate to get a Stun Gun inside an open crate.
 * One can be found during the fight with Barrett, in one of the boxes.
 * At least two Stun Guns can be found in the news building in Montreal.
 * A Stun Gun can also be found at Sarif headquarters in a secluded underground area near the helipad. The Stun Gun itself is behind a level 5 locked door.
 * A Stun Gun and some darts can be found in an alley due west of The Hive in Kuigan District in Lower Hengsha. Either using the jump ability or stacking a box to get over the fence.
 * A Stun Gun and darts can be found in Tai Yong Medical. Through a vent in the section D control room occupied by two guards.