- Estimated achievement difficulty: 7/10
- Offline: 37 
- Online: 0
- Approximate amount of time to 1000: 40-50 Hours
- Minimum number of playthroughs needed: 2
- Missable achievements: None – Chapter Select
- Does difficulty affect achievements: Yes [Check Roadmap/Guide]
- Unobtainable/glitched achievements: None
- Extra equipment needed: No
After a long ten year hiatus, Eidos Montreal has finally resurrected the classic stealth title of the early 21st century: Thief. This game takes place in a dark, Victorian/Steampunk fantasy world in a city simply named, “The City.” You play as the master thief, Garret, and must steal from the rich and uncover the dark secrets of The City all while using stealthy maneuvers to achieve your goals. The gameplay is choice-driven, which means you can tackle each encounter whichever way you choose to do so. As far as the achievements are concerned, you will unlock your usual “secret” achievements upon completing all eight Chapters within the Story. There are various sets of collectibles to be found, tasks for spending a certain amount of gold, and a behemoth of an achievement for completing the entire game without killing anyone or knocking anyone out. Make sure to stick to the roadmap and guide below in order to obtain your full completion!
Story (Rogue/Thief Difficulty):
I would highly suggest taking your first playthrough of this game very slowly. Set it on one of the easier difficulties so that you can get a nice feel for the basic controls, enemy A.I. behavior, and overall mission level design. During this first playthrough, nine of the twelve secret achievements will come naturally as you complete the Prologue and all eight Chapters in the Story. You should also focus on obtaining "Obsessive Compulsive" and the secret achievement, "Two-Faced", within the very first Chapter of the game. Additionally, "Focus on the Task at Hand", "One Step Ahead", "Hail of Glass", and "Health Hazard" should also be attempted while working through the Story. Also remember to be constantly picking pockets for the "Sleight of Hand" achievement. Lastly, remember to be on the lookout for collectibles, hidden areas, and side jobs for a total of nine additional achievements.
There a number of miscellaneous achievements that can be completed along the course of your first playthrough, subsequent playthroughs, or even after you have completed the game. While you are completing story-based missions, you will want to complete the optional “Thieving Objectives,” which yield "Dark Archer" and "Legend in Leather". Then, you will need to locate all the Hidden Areas around The City for both "Hidden Agenda" and "Finders Keepers". Lastly, completing all the side quests will net you both "Working Overtime" and "Dastardly Deeds". Completing everything should see you well over the fifteen hour mark needed for the "More Heist Less Speed" achievement.
Second Playthrough (Custom Difficulty):
This second, full playthrough of the Story will be much more tedious and stressful, as you will want to try to stack many of the more difficult stealth-related achievements in the game. First off, the achievements that you’ll want to stack are as follows: "Something to Prove", "Mint Condition", "A Moral Victory", and "Clear Headed". These achievements will require you to complete three consecutive Chapters without taking damage and completing the entire game without killing anyone, knocking anyone out, or using the Focus ability. Along the way, you will naturally unlock the "Child of Shadows" achievement as well. Remember, this entire playthrough is on the Master difficulty for the "Hard Times" achievement, so be prepared! For a detailed breakdown on how to set up your custom playthrough please see the relevant section of the guide.
NOTE: The reason we suggest you complete the harder stealth related achievements during the, admittedly, difficult custom playthrough is because the modifiers used in our strategy are not only the easiest combination but lend themselves very well to the stealth based achievements. While it may be easier to obtain "A Moral Victory" on a lower difficulty level you will still likely need to play through custom with the 'No Kill, No Knockout' modifier turned on anyway, as it is worth a lot of points and any other modifier of equal value would make this playthrough much, much harder. Given this all you would be doing is adding another complete playthrough on your road to the 1000.
Challenge mode is a fun little departure from the main game whilst still staying true to what Thief is all about. Loot! Challenge mode ships with 2 maps, Northcrest Manor and The House of Blossoms, and offers you 2 game modes to choose from, chain gain, special loot and chain gain limited. In Chain Gain you have to loot as many items as possible within 60 seconds of each other to score maximum points, Special Loot has the same basic premise running throughout as chain gain but adds in special loot items that you can can find using a hot/cold meter in the top left corner and finally chain gain limited is the same as chain gain with the added crutch of an overall time limit to finish your run in. There is only one achievement gained from challenge mode, "Modesty Denied", for more detailed information please see the relevant ares of the guide.
At this time, you should only have a few achievements left. If necessary, roam around the open world in order to continue working towards the "Sleight of Hand" achievement. Likewise, If you are missing any Hidden Areas or Side Jobs, proceed around The City, loading up previous Chapters where necessary. For the "Priceless" and "What’s Yours is Mine" achievements, make sure to keep hunting down those pesky collectibles! If you haven’t already unlocked them, this would be a great opportunity to pick up "Quickly Pick a Lucky Lock", "Cache Dispense", and "All That Glitters". Moreover, refer to the guide below in case you missed the the final two secret achievements and still need to grab them.
As a general reminder, you can replay chapters by returning to their starting point in the open world. These starting points are usually indicated by a glowing gate or door. Take note, however, that these points are not marked on your map, so you will have to remember where they spawn. Once you choose to replay a Chapter, all of the statistics and challenges from your previous run will RESET. This means that the Thieving Objectives for each Chapter are NOT cumulative, but not missable, either. The collectibles you've found within that Chapter will still be in your inventory and won't be lost, only the statistics will reset.
Overall, Thief is a very enjoyable title for any fan of the stealth genre. While the narrative is unfortunately forgettable, the art style and classic thieving and sneaking gameplay is where the game truly shines. The achievements are both overwhelming and a tad dry, but it shouldn't be too tasking to snag them all across your playthroughs. Whether your a fan of the series, a hardcore stealth gamer, or looking for a new game to try out, Thief is sure to suit your needs due to its compelling and exciting gameplay mechanics. Don't give this game a miss.
[XBA would like to thank Metabolic XBA for this roadmap]