Tools of the trade
On top of that, Corvo's got a sizable and versatile arsenal at his disposal. He can teleport small distances, see through walls, freeze time, and summon rats; a pistol's useful in a fight, while a crossbow with sleep-inducing bolts is good for sneak attacks. Re-wire tools let you turn enemies' defenses, like walls of disintegrating electricity, against them, and silent, razor-spewing trip mines make deadly traps.
Every tool and ability is available from the start. This way, you're always free to choose your path. Each ability has two levels, and locating the Runes required to upgrade them is as easy as equipping a magic, talking heart and seeking the objective marker. It sounds cheesy, and it is—but it also ensures that players who don't want to painstakingly explore every nook and cranny can still upgrade their abilities.
That's the type of clever design quirk that Dishonored exhibits at every turn. Another is the fact that each ability is far more versatile than it may initially appear; Windblast can harm enemies, but it can also break down some doors. Possessing animals or people is great for sneaking around, but you can also possess into an enemy in the middle of a fight. Blink, the teleportation skill, is essential for combat, stealth, and exploration. Even the Rat Swarm, which seems at first to have little use outside of combat, can be summoned by stealthy players to devour bodies and ensure those kills are never discovered.