Non-Lethal Gameplay (DX)

Deus Ex provides the player with the option of using non-lethal methods to take down enemies. Except for one character whom the player must kill during the course of the game, the choice between lethal and non-lethal approaches is largely the player's preference. In the early missions, the player's choices regarding lethality will affect the reaction of non-player characters.

Overview
Human non-player characters are rendered unconscious if their last bit of health is removed by any of the following weapons, which are considered to be non-lethal weapons:


 * Baton
 * Riot Prod
 * Mini-Crossbow (when loaded with Tranquilizer Darts)

Items that emit tear gas or halon gas (gas grenade, pepper gun, and fire extinguisher) can also be regarded as non-lethal weapons. However, tear gas and halon gas are only capable of blinding and stunning targets, and are not capable of rendering them unconscious. Unconscious enemies cannot be revived, whether by the player or by their allies.

All NPCs that are not invincible can be rendered unconscious, with the sole exception of Anna Navarre, who cannot be rendered unconscious because she is fully immune to the damage types inflicted by the baton, riot prod, and tranquilizer dart. Navarre is the only character in the entire game that must be killed by the player, unless console commands, bugs, or exploits are used to circumvent her death.

Non-lethal incapacitation provides no inherent gameplay benefits to the player, except against men in black and women in black. MiBs and WiBs explode when killed, thereby destroying their inventory. Therefore, the only way to loot their inventory is to render them unconscious, so as the avoid triggering their self-destruct explosion.

Animals, including transgenics, cannot be rendered unconscious by non-lethal weapons. Non-lethal damage from the baton or the mini-crossbow's tranquilizer dart will cause the animal to die, instead of rendering it unconscious. The riot prod does not inflict any damage on animals, but will cause non-transgenic animals to flee.

Dead vs. unconscious
The game distinguishes between killing characters and rendering them unconscious only in certain specific contexts listed below.

In all other situations (which includes most of the entire game after the third mission), the game does not distinguish between killing a character and rendering that character unconscious, for purposes of dialogue and other story-related interactions. For example, when the player is tasked with assassinating a certain character in the third mission, the game will consider that character to be killed even if only knocked out. Similarly, when the player is tasked with rescuing another character in the 11th mission, the game will similarly consider that character to be killed even if only knocked out.

A difference, however, is the reaction of scripted pawns to unconscious bodies as opposed to dead ones. The internal flag bNotDead is used in combination with the Unconscious string to skip the entire carcass discovery resolution process (which distresses and alerts any scripted pawn with the bHateCarcass stimulus or bFearCarcass fear if they have seen the carcass, and may cause them to turn hostile or run away depending on the corpse and killer's alliances by setting the bCares internal flag). An unconscious body does not emit blood nor take any indirect injury (except explosions) but can still be killed if directly hit past the body health damage threshold with a lethal melee damage type (indicated by a gradually darkening tint). Once the unconscious body fully goes dark, it is gibbed and marked as killed by the last damage instigator. This can be seen with Karkians and Greasels (especially the latter, as the Poison damage type will always knock a victim unconscious) using the Munch damage type even on unconscious bodies, gibbing and killing them after enough hits.

"Aggressive" flag
During the first mission on Liberty Island, the "M01PlayerAggressive" flag will be set to "true" if the player kills more than 5 out of the 28 NSF terrorists on Liberty Island. Kills made by NPCs (i.e. UNATCO troopers, Gunther Hermann, or the two UNATCO medium security bots) do not count, however kills by turrets reprogrammed by the player do count. For purposes of this flag, rendering NSF terrorists unconscious does not constitute a kill. This flag affects dialogue with Tech Sergeant Kaplan, Paul Denton, Private Lloyd, and generic UNATCO personnel in the UNATCO Headquarters.

The aggressive flag will no longer play any role after the very first mission but may have been intended to. It is set to expire at the beginning of Mission 6, possibly because the player does not encounter any NSF terrorist from here on.


 * Paul prefers non-lethality. If the flag was triggered, Paul will say: "Yeah, well, pace yourself. You killed a lot of people tonight." Otherwise, he will instead say: "Just keep a level head. You're doing well so far."
 * UNATCO personnel other than Paul will compliment JC for acting aggressively. For example, Kaplan will tell JC, "Heard you cleaned the place out." Otherwise, if JC took the non-lethal approach, Kaplan will say: "Heard you went a little soft on the NSF; the guys had to mop up for you."

Specific characters
If the player fails to obtain the surrender of NSF commander Leo Gold, Paul Denton and Joseph Manderley will react slightly differently depending on whether Leo Gold was killed or rendered unconscious. Additionally, in the third mission, Harley Filben will charge only 500 credits for Curly's password if Leo Gold was rendered unconscious instead of killed (if Leo Gold was killed, Harley will charge 1000 credits).

If the player attacks the UNATCO trooper that greets JC Denton at the top of the Statute of Liberty, Joseph Manderley's dialogue will be slightly different depending on whether this trooper was killed or rendered unconscious.

BatteryParkSlaughter flag
During the Battery Park segment of the second mission, the "BatteryParkSlaughter" flag will be set to "true" if more than 1 of the 5 NSF terrorists guarding the above-ground portion of Castle Clinton are killed. Rendering NSF terrorists unconscious does not constitute a kill. However, the game makes no distinction as to who made the kill, whether it was by the player or by Anna Navarre or her squad. Therefore, in order to avoid triggering this flag, it is necessary to avoid triggering any hostilities between the NSF terrorists and Anna Navarre's squad.

This flag affects interactions with Anna Navarre, Sam Carter, and generic UNATCO personnel.


 * Anna Navarre will react favorably if the flag was triggered, telling JC, "You are not afraid to kill; I am pleased. The last thing I would expect from the brother of Paul."
 * During the second visit to the headquarters (at the start of the third mission), Sam Carter will be more favorable toward JC if flag was not triggered. In this case, Carter will also provide ammo to JC.

TenderloinSlaughter flag
During the firefight between NSF and UNATCO forces in Hell's Kitchen, if the player manages to personally kill (rather than render unconscious) at least 3 of the 5 NSF terrorists, the TenderloinSlaughter flag will be set to "true". This flag affects the random dialogue lines of UNATCO troopers in the area.

Dealing with Sandra's pimp
This is one of the rare cases where multiple distinctions are made. Sandra will have various reactions depending on how the pimp was dealt with (intimidating the pimp has its own flag). Because the Pimp_Dead flag is the only check made if Johnny goes down, a funny situation where Riot Cops are patrolling right as Johnny goes hostile, rushing in and either knocking him out, killing him or causing him to flee from low HP can occur, resulting in Sandra (and Janey) thanking the player for killing or injuring the pimp.
 * If JC intimidated the pimp: "Hey, you shouldna threatened Johnny. Soon as JoJo finds out..."
 * If Johnny was injured (but is not yet dead or unconscious at the time of the conversation, or managed to run away): "Hey, you shouldna fought Johnny. Soon as JoJo finds out..."
 * If Johnny is flat on his back by the time JC talks to Sandra (Pimp_Unconscious is not checked, so he will be merely treated as dead): "Hey, you shouldna took down Johnny. Soon as JoJo finds out..."

Because the pimp makes no further appearances in the game and is no longer mentioned in dialogue after completing Janey's mission, it is also possible to dispatch him after talking to Sandra and/or Janey. Doing so will not affect JC's lines with Sandra's father as he is referring to another kind of nuisance.

3rd Mission
During the Brooklyn Bridge Station segment of the third mission, El Rey will give the player the optional objective of killing Rock. If the player knocks out Rock instead of killing him, the dialogue when reporting back to El Rey will be different.

6th Mission
In the Wan Chai Market segment of the sixth mission, killing or knocking out Louis Pan will trigger Gordon Quick to give slightly different dialogue.


 * If Louis Pan is killed: "I will warn you once: do not assault our agents or representatives. The boy... he was a good earner.
 * If Louis Pan is rendered unconscious: "I will warn you once: do not assault our agents or representatives. The boy... he is a good earner."

This happens with Paul's current state as well in Gordon Quick's very first barks:
 * Gordon Quick: "The Luminous Path is closed to gwailos."
 * JC Denton: "Paul is/was no friend of the West."