I have heard numerous times that various sources, including the developers, have claimed that killing enemies during D6, The Train, or Red Square do not count towards killing humans. I have not personally confirmed these claims, but I have confirmed that the steps listed in this guide are how I got the achievement. This guide is not meant to be authoritative by any means, it's simply a way to prevent the frustration of playing through the game and not getting the achievement.

This can be an incredibly difficult achievement to earn, since necessity is open to interpretation. You may have seen guides that say you can do certain things, or that you can't do certain things. Well, after finally getting this achievement for myself, I've decided to share my knowledge with other people, in the hopes to finally end the arguments once and for all.

I've decided to split up the parts that are debated into sections, rather than just giving a simple step-by-step list. In doing so, I hope to avoid ambiguity and save players the frustration of following vague instructions only to not earn the well-deserved achievement.

Early in the game, you are shown that by approaching enemies, you have the option of either killing or knocking them out. It is important to note, for the sake of the achievement, that knocking out an enemy is not the same as killing. However, the only way to knock out an enemy is by walking up to an enemy and using the appropriate button ("E" is the default). Any other methods of attack will count as a kill.

You can use any difficulty level you want for this achievement. I used Easy mode to get this achievement, so I assume that if you can get it on Easy, you can get it on all other difficulty levels. However, some parts of the game are difficult when you're not allowed to kill humans, so I would highly recommend sticking with Easy mode.

(Note: I have not tested how changing the difficulty mid-game affects getting the achievement. I don't think it would be a problem, but since I already have the achievement I can't test it. I only mention this because certain parts of the game, such as The Chase, are near impossible to finish unless you're on Easy mode. If anyone could test this, it would be greatly appreciated.)

The actual criteria for the achievement is not to kill any Humans unless you absolutely have to. In other words, this means that all non-human mutants can be killed. I've heard otherwise, but I do not believe the mutants at the very beginning count against the achievement, at least in my experience. I do know for absolute certain that for the rest of the game, as long as the enemy you are facing is not a human, you can kill it.

As long as you have not killed any human enemies except for the ones that are necessary (which I will address in the appropriate section), you can reload checkpoints as much as you want without worrying, with one exception: If you end up killing a human enemy when you're not supposed to, you must start the game over again.

The player is allowed to die while working towards this achievement. In addition to simply being killed by the enemies, you are allowed to let yourself get killed as an alternative to reloading checkpoints.

While you cannot kill most of the human enemies, you do not necessarily have to knock all of them out either. You can simply sneak by them if you so choose. In fact, there are some instances where it is impossible to knock out enemies without being noticed. You can simply sneak by them if you so choose.

Despite what is suggested by the name of the achievement, you can still acquire it if you get spotted. You can run up to enemies and knock them out, you can reload the checkpoint, or you can simply run past your enemies to the end of the area. As long as you do not kill any enemies, you'll be fine.

For the most part, you shouldn't have much problem knocking out enemies. However, there is one bandit sitting on a railcar with a lantern on his left side that many people have had trouble knocking out. As such, I felt I should explain how to go about knocking him out.

First, you should not extinguish his lantern. Instead, approach him from the darkened right side, and stand near him, and jump towards him. If you are playing on a non-Ranger difficulty level, the prompt for knocking him out should show up.

As far as I am aware, you are not allowed to kill any enemies during The Chase. This includes the enemies that are shooting at you while you are riding the Railcar being driven by Khan. All you can do is duck and heal yourself. You need a minimum of 3 medkits, but I highly recommend having 5. Be sure to use them sparingly, because there's a checkpoint in the middle of the ride, and if you don't have any medkits, you'll probably have to start the chapter over again. Don't fret if you end up dying a lot, you can always reload the checkpoint as long as you didn't kill any human enemies.

As for the train itself, it doesn't matter how many medkits you have. You can loot medkits off of knocked out enemies. If you don't feel like knocking them out, you can just run past them. As long as you don't kill any of them, you're that much closer to getting the achievement.

[Update: September 26, 2021: A user named blackjacksikes has confirmed that you are allowed to kill enemies in this section without failing the achievement.]

As far as I can tell, you are not allowed to shoot any enemies here either, except for Pavel. I didn't even attempt to shoot him while he was taunting me, I just hid and punched enemies as they came at me, and waited until he said he was getting impatient and opened the front doors. You may be able to shoot at Pavel to prompt it earlier, but I didn't risk this because I didn't want to accidentally hit one of his snipers.

Once the front doors open and you make your way up the stairs, you can shoot Pavel. Doing so is necessary to proceed. This is one of the only times in the game you are allowed to.

Be sure to save him after he gets grabbed by the scary arm monster thingies. I believe just leaving him there counts as killing.

[Update: September 26, 2021: A user named blackjacksikes has confirmed that you are allowed to kill enemies in this section without failing the achievement.]

As far as I know, this is the only part of the game that you can kill any non-mutant enemies. A user named Sitru has confirmed that you can shoot pretty much everyone during this level and still acquire the achievement. However, for those who prefer to err on the side of caution, it is possible to get through the game with killing only two enemies.These enemies are:

1.The Tank - Not really a human, but definitely not a mutant, and if you don't destroy it, the game ends.
2. The Flamethrower Man - What's important to keep in mind is that, if you're erring on the side of caution, you can only shoot the guy with the flamethrower, not his guards. At one point, the guards leave an opening wherein he shoots fire for no particular reason, but this is not the only opening. As they approach, you can jump atop the wall right in front of you, and shoot at him without worrying about his guards being in the way.

There has been some confusion as to whether or not looting gasmask filters from unconscious enemies counts as killing. As of June 26, 2014, a user by the name of Dracses has confirmed that you can loot filters off of unconscious enemies and still earn the achievement.

If you've followed all the guidelines, you should receive the achievement after Artyom grabs the handle on the detonater, at the start of the ending cutscene that plays depending on which ending you've earned.

I hope this guide has been helpful, and I hope I've cleared up the issues that are associated with this achievement.

This guide is based mainly on personal experience in acquiring the achievement, and there are some variables which remain uncertain. If you have any additional information that I have not gone over within the guide, please let me know through the comments and I will update the guide accordingly.

I politely request that you carefully read through the guide before asking a question in the comments. If there can be no answer found within the guide, that is when you should ask in the comments. I may not get back to you immediately, but I will answer as soon as possible.