The recent discussion has forced me to get back into the games. I reinstalled Deadly Shadows recently and played that, then I learned of the Thief 2X project and am part way through that. I think once I'm finished I will have to reinstall Thief and play through the whole series- not for the first time. That should give some indication of how good these games are.
Thief 3 was made by Eidos after the original developers, Looking Glass Studios, folded. They did a good job... overhauled the engine and produced something that both looks gorgeous and is recognisably a Thief game. It has flaws- some of the additional features aren't that great, and I think they broke some of the tools, for example, but they're forgiveable. In particular, the Shalebridge Cradle level is masterfully done and you'll hear about it a lot- PC Gamer UK even ran a several page article about *just that level*. But mostly forgiveable because it's an impressive achievement to produce something that is recognisably a Thief game.
The first two games are definitely worth tracking down. While the older graphics can't compare to Deadly Shadows, you'll find that in a very short time, it doesn't matter. They create atmosphere by the truckload; each level is filled with little details, both aural and visual, that bring the game world to life and force you to smile grimly at it or shiver in horror, like overheard conversations or the notes and diaries scattered around. It immerses you, and you find yourself buying into the game- sure, you *could* probably take a lone guard, but I can practically guarantee that when you come face to face with one unexpectedly and he jumps back in surprise and raises his sword, you're going to be too scared to do anything but run like hell and cycle frantically through your inventory for an escape tool, hoping to find a safe spot or take him out before he can alert all his friends.
The levels are all huge and filled with stuff to find. As well as loot, each has at least one secret hidden in it, which bring up a little message and satisfying sound when you do. Each also has its own distinct feel; there are mansions and temples, city streets and tombs, etc etc. Some are straightforward steal-everything-that-isn't-nailed-down affairs; some start off simply but quickly build to the realisation that something is very, very wrong; one is filled with awesome Indiana-Jonesesqe traps. And every so often you find one whose flavour is horror- I'm still scared of one of the Cathedral levels. All are woven into a similarly immersive storyline, drily narrated by Garret, with each game exploring one of the big organizations in the game world, be they magical or steampunk.
They're also very replayable. Partly due to size- there are dozens of possible routes through each level, and you probably won't see everything first time. Plus each has three difficulty settings, which provide additional goals, more and differently placed enemies, and sometimes open up additional areas or alter the levels slightly to keep you on your toes. Oh, and they're only roughly mapped- unless you manage to steal a better map, you have to make do with Garret's scribbles and your compass, which is as it should be. (It drives me crazy how Hitman gives agent 47 a map which shows the exact layout of everywhere he goes complete with real-time location and facing of every single person there. How is that supposed to be possible? Thief instead has you lurking in shadows waiting to see if a guard patrols this hallway, crouching in a hiding place listening to the approaching footsteps of a suspicious guard, and listening at doorways for clues to what's behind them.)
The equipment builds to a sizeable collection of cool gadgets; my perennial favourite are flash bombs, emitting a blinding light to buy you a few seconds. There's also expoding things when you need to do a lot of damage or create a distraction, water arrows that let you put out torches (or clean up bloodstains...), gas arrows for quiet knockouts at a distance, various mines, potions for long falls, and a few stranger things.
There are downsides- mostly that the AI and engine have their limits, but you have to expect that from games as old as this. Neither is by any means shabby, and they're more than made up for by the scripted events, and even unspeakably cool moments that emerge without the need for being scripted- for example, jumping right over the heads of two guards to get into the window of your own heavily-guarded second-storey apartment, with them none the wiser. (Of course, you're free to climb up the fire escape around the back instead if you want.)
tl;dr: They're awesome. Play them.
[ May 02, 2008: Message edited by: McDoomhammer ]