Dishonored

One way to get this achievement is that you can render a guard unconscious either by using choke-hold or a sleep dart (you'll know he's not dead because it will pop up unconscious when you look at him), and then pick him up and throw him through a wall of light, which are the things that look like someone strapped a bunch of wires to a wall and if you try to walk through them you get fried. He'll disintegrate and the achievement should unlock.

Edit: Some people apparently had to carry the guy through the wall personally to get the achievement. If you have to do this it will kill you so just make a save right before you do it.

I saw it seemed real simple in the mission where you have to get to Sokolov's home. There's a torn down building/wall area where some guards are holding hostages (a dead guy, a woman and guy walking back & forth) behind a wall of light. You can rewire the wall of light then go inside with the hostages and when the guards see you ( they're stupid) they run right into the wall of light. (I had already gotten the achievement earlier, but did take note of this one. If it works someone please let me know)

The first chance you come across a Wall of Light is in the High Overseer Campbell mission.

When you get dropped off by Samuel, make you way round along the river bank, when you come to a small sewer pipe coming out between two sets of steps, there is a guard on the upper right hand side. He walks in the same direction that you need to go, so either dispatch him (lethal or non lethal) or just stay behind him as he walks away from you.

Keep going until you come across some steps on your left hand side. If you chose to follow the guard, he will walk up them and pause at the top before turning round and going back down to where you have just come from.

Go up these stairs and you will see a set of stairs in front of you running horizontal to your current direction. Go up these and using blink make your way up onto the street lights or onto a shop front on your right hand side as you go up the steps.

Once your on a high perch, make you way over to the guard station (the metal building on the far side of the map near the Wall of Light).

There is a guard inside who doesn't leave unless you have been discovered. So if your going through the campaign in stealth, then you may want to knock the two guards out that patrol around the area of the guard station (one of the guards may go down the steps that is just to the side of the guard station to patrol the road that you crossed earlier) there are also 2-3 guards on the bridge on the left (you see them throwing dead bodies off the bridge near the beginning of the mission).

NOTE: You can leave the guards on the bridge alone as they never move unless your detected.

By taking out the two guards that patrol around the guard station silently, this will allow you to approach the guard station via the back and through the main door (there is a hatch on the roof that you can open, but the guard inside will see you as soon as you drop through.) and knock him unconscious.. DO NOT KILL HIM!

NOTE 2: There is a rewire tool in the guard station that you can use to rewire the Wall of Light just outside the guard station. The box to do this is just to the right of the Wall of Light (it's a small grey box with two small doors, attached to a normal wall.)

NOTE 3: If your going through the campaign in a non stealth manner, killing everyone you come across, then make sure you leave one guard alive, this can be done by killing all the other guards in the area, then using blink, get up onto a high ledge (the guard station is the easiest to get up on) and the guard will loose sight of you. Hide until you can get behind him and knock him unconscious.

Once you have the rewire tool from the guard station and at least one guard unconscious, proceed to the Wall of Light control box, open it and press (X) to rewire it, this means you can pass through it safely, but guards can not.

Go back to the unconscious guard, pick him up and carry him to the Wall of Light, then simply throw him into it to kill him and the achievement will unlock.