Dishonored

By far the easiest way to do this achievement requires no patience, skill, or even that much time.

Once the mission starts, open the door in front of you and sneak behind the first guard and kill him.
It may take a few times, but in the long run this takes far less time than retrying until you avoid everyone.

Failing after a ten minute run is much more frustrating than just hitting retry. I redid this ten times and this guard ended up being my target two of the ten times.

Just in case anyone needs a visual aid to getting this achievement or just confirmation that by killing the first guard can eventually get you the achievement here's a video.

This challenge sends you looking for four clues to determine who your target is. If you kill anyone your target will flee. If too many unconscious bodies are found your target will flee. Once your target runs it is all but impossible to catch them, so a stealthy approach is mandatory.

For this achievement you must successfully assassinate your target without using ANY active powers, including Blink!!! Sneak, sword, crossbow, and pistol are your only options so make the most of your sleep darts and choke hold.

Your target will NOT be marked as a waypoint, so you will have to actually look at potential targets to determine if it's the right victim in your crosshairs.

The clues will tell you what color clothing they are wearing, if they are wearing a hat or mask of any kind, if they are male or female, and if they are a noble, a member of the city watch, a maid, or a courtesan.

You will want to duck under curtains and choke everyone you come across then hide the bodies behind curtains. I got this by sneaking out of the hiding area and choking the first couple guards I came across. I worked from the perimeter inwards knocking people out as needed. Keyhole spying and leaning will be your best friends. If you come across two foes and there's no way to get the clue without alerting them just sleep dart them both quickly, then drag the bodies away and hide them behind a curtain.

I found that by keeping 2-3 "stashes" of bodies it was easier for me to locate my target once I identified them. This will also keep the foes from noticing bodies and running away.

First of all let me just say that this is entirely upon luck.

I started the challenge, walked out of the double doors and snuck up behind the guard right in front of me. I went to subdue him when my finger slipped from the button, causing the guard to counter my attack. This lead to the target being alerted. Out of frustration I then ran to the first person I saw fleeing, slashed them up... It was the target. 15G for 22 seconds work. If you guys try that you may get lucky like me. I'm sure with enough tries you'll eventually get the target.

Good luck!

Hello fellow achievement hunters.

This achievement requires PATIENCE above all.

You CANNOT KILL ANYONE other than your target.

You can subdue them nonlethally (choke, sleep dart, etc.).

Patrol the outer halls, knock out guards systematically, and hide the bodies. Have a semblance of what the guests look like as you are clearing the rooms, because your target does not have an arrow over their head once you know who they are.

Getting detected is ok, as long as you sleep dart them before they alert any guards.

Hope I can help, and good luck!