The tools of the trade vary greatly between different games. While most first-person games tend to have a limited selection (generally a list of firearms of increasing power), the likes of Thief and Deus Ex provided weaponry, tools and more to the player. With Dishonored, the arsenal is comprised of three parts: Weaponry, Magical abilities and special tools.
The weapons of Dishonored are the least interesting of the three. Your first acquisition is a sword, for lethal takedowns and melee combat. Next up is a wheel-lock pistol, and finally a small crossbow. The pistol is noisy and inaccurate, and not really something you would recommend using. The crossbow has a wider variety of uses, with different darts for different uses (normal, sleep, incendiary). At various points you can buy upgrades for all of these (and for other equipment too), which makes them more useful to use.
The magical abilities are far more interesting to me. Once you have had your meeting with the Outsider (in a dream world full of foreshadowing) you are first given the ability "Blink", which allows for short-range, line-of-sight teleportation. This is immeasurably useful, allowing quick and easy access to otherwise inaccessible areas. Following this, you are given a mechanical heart. This provides a great mechanic to the game. The heart will guide you towards runes and bone charms, so you can upgrade your powers, but it also gives you information about the area you're currently in. The haunting voice really does provide extra atmosphere when it tells you little secrets about the people and places you see.
A lot of the other powers are situational, the ability to possess animals, calling forth a rat plague and so on. One that gets a lot of use from me is the Dark Vision power. This allows you to see nearby living creatures and their field of view, making it considerably easier to sneak up on unsuspecting guards. It is so useful though, that at times I spend quite a lot of time in this improved vision mode. Especially since the upgraded version highlights items of value.
Lastly, there are a few pieces of equipment that can be carried with you. There's grenades, which are fairly standard and not something I would rely on (you know you've really given the stealth bit up when you're throwing explosives around!). The Spring Traps are just proximity mines by another name, and up to this point I haven't used one of them either. I'm not really sure what situation they are designed for. Rewiring tools are far more useful, for hacking alarms and other electrical devices. Often though, the circuit boxes for such items are in very awkward places, and it can be easier to avoid the confrontation altogether.
Generally I've found myself relying a little too much on violence, and have toned that down a little for the remaining missions. I have the urge to "complete" levels by removing all guards and so on, but this isn't really the point of the game. Finding sneaky ways past everyone is much more satisfying, providing you don't want to try and collect every coin and rune that you can find.
Hopefully for the next part I'll have finished the game, and will be giving my final thoughts!