Non-Lethal Gameplay

Games in the Deus Ex series provide the player with the option of using non-lethal methods to take down enemies. Some players choose to do entire walkthroughs of the game without killing enemies. Such playthroughs are sometimes called "non-lethal" or "pacifist" runs.

Games released after Invisible War implement pacifist runs as achievements.

Deus Ex
Deus Ex includes several non-lethal weapons, such as the baton, riot prod, mini-crossbow (when loaded with tranquilizer darts), gas grenade, and pepper gun. The baton, riot prod, and tranquilizer darts are capable of rendering targets unconscious for the remainder of the mission. In the early missions in the game, the player's choices regarding lethality in certain situations will affect the reaction of non-player characters.

Deus Ex: Invisible War
In Deus Ex: Invisible War, non-lethal weapons include the baton (which is a melee weapon), the bolt caster (which is used to tranquilize targets from a distance), and gas grenades. Power armor Templar troops cannot be knocked unconscious.

Deus Ex: Human Revolution

 * Achievement: Pacifist

Deus Ex: Human Revolution was the first game in the series to implement a pacifist achievement, which requires the completion of the entire game without causing a single death (except for bosses). Human Revolution also introduced a takedown mechanic that allows the player to perform non-lethal takedowns of enemies without spending any ammunition. Alternatively, the player can render targets unconscious by using weapons, such as a stun gun, P.E.P.S., tranquilizer rifle, or gas grenade. Unlike the previous games in the series, unconscious enemies can now be revived by their allies.

Deus Ex: The Fall

 * Achievements: Starting Off on the Right Foot and Natural Born Pacifist

Deus Ex: Mankind Divided

 * Achievement: Pacifist (Mankind Divided achievement)

Similar to Human Revolution, Deus Ex: Mankind Divided offers a pacifist achievement, although the requirements for attaining the achievement have been somewhat relaxed to permit indirect kills, such as killing by triggering an electrical hazard. The story-based DLCs have their own achievements for pacifist runs within those DLCs (Clean Sweep for System Rift and Code of Conduct for A Criminal Past). Mankind Divided introduces new options for non-lethal combat, including a non-lethal configuration for the Tyhpoon and a new augmentation (TESLA) that is capable of stunning multiple targets at mid-range.