General Advice & Exploration
- Make sure to play Thief Gold rather than vanilla Thief: The Dark Project if possible. Gold adds three new missions interwoven into the existing story, overhauls a couple of others and generally tweaks, optimizes and removes bugs in all of them.
- Installing TFix is recommended, it's a community-made fixpack that improves compatibility, includes widescreen support and tweaks/fixes a variety of things.
- Difficulty level primarily affects your number of objectives, amount of loot required and who you're allowed to kill. Some areas pertaining to extra objectives are only accessible on higher difficulties. Unless you're new to the genre and not very confident, playing on at least Hard is a common recommendation to get the most out of the game.
- You can't save up money, the amount of funds you have available for buying things between missions is always equal to the amount you looted in the previous mission. Always buy as much as you can and need.
- Levels tend to be quite large and your maps are usually vague at best, make good use of your compass and any landmarks that help you from getting hopelessly lost.
- Keep a sharp eye on your surroundings, many goodies are hidden in places that aren't immediately obvious and people tend to keep their valuables out of sight.
- It's good to read the various scrolls and books you come across. There's lots of great world building there, as well as clues to secret caches of loot and hidden areas.
- Most valuables that can be looted show up as golden to differentiate them from worthless items, e.g. a golden wine bottle can be looted whereas a regular-looking wine bottle can only be picked up and thrown. TFix might make the difference slightly less obvious.
- Some wall hangings can be cut down, usually to no effect but you might find the occasional surprise. If it's something you can't cut down you'll probably just hit the wall with a loud clang instead though, so quicksave first if you're not sure.
- Two missions, 'Down in the Bonehoard' and 'The Haunted Cathedral', have points where Fire Arrows are requires to progress, so try to not burn through all of them. Thief Gold adds infinitely respawning enemies to those levels that always drop them on death to ensure you can't get stuck.
Stealth & Dealing With Enemies
- Stick to the shadows (keep an eye on the light meter), move quietly (watch your speed and be careful of loud surfaces) and find havens to evade enemy patrol routes. If you want to take enemies out, sneak up on them, render them unconscious and hide their body. Enemies are intelligent enough to react if something looks out of place, such as a locked door being open.
- Unlike in many modern games, crouching and sneaking ("creeping") are separate modes from each other, so make sure you're not just crouching if you want to fully minimize your presence.
- Having a weapon out slightly increases your visibility, so keep things sheathed when trying to be sneaky.
- In addition to leaning sideways to peek around corners, you can also lean forward which is a very handy maneuver for taking out unaware enemies who are walking towards or past you. The default key is the awkward Alt+Shift+W, but you can rebind it to whatever you want.
- Guards have very poor peripheral vision and often react pretty slowly, so you can potentially get away with some pretty bold maneuvers such as running and knocking people out right next to each other.
- Some human NPCs carry money pouches or keys on their belts, you can either pickpocket them or grab them after taking the person out.
- Flash Bombs are very useful, especially on Expert as even enemies that have already spotted you can be knocked out with the blackjack while they're blinded. Make sure to aim them in front of enemies while trying to avoid being caught in the flash yourself - this can sometimes be easier if you drop the bomb with the Drop Item key instead of throwing it.
- Zombies can be a pain, but they're easy to evade and there are several ways to permanently deal with them. In addition to Holy Water -dipped Water Arrows, both Mines and Fire Arrows (aim for the abdomen) make short work of them as well. 3-5 Flash Bombs will also do the trick, and due to their blast radius they're particularly handy in taking out larger groups.