But if we could give you just one tip to help you survive your stay in Dunwall, it would be this: wait. Headstrong players may be able to bludgeon themselves through guard patrols through blunt force, but playing this way is a terrible drain on your resources and will leave you significantly weaker for the path ahead.
Instead, don't be afraid to lurk in the shadows, observing enemy patterns and scouting your environment. You'll be amazed at the opportunities that will fall into your lap if you hide behind a bin and do a spot of people-watching. Two NPCs will meet and have a revealing conversation perhaps, or a fleet of rats will pass by, ripe for the possessing. In Dishonored, as in all walks of life, good things come to those who wait.
11. Respect the rat
Be careful where you leave unconscious bodies if you're trying for a clean playthrough. Drop 'em where passing rat packs can reach them and they'll scoff him or her whole while you're on the other side of the map, minding your own business.
12. Concerning Tallboys
Tallboys are, in a word, gits. But there's an easy way to polish them off in one hit - if you've got a steady aim. They're fueled by a canister of Whale Oil, which they lug around on their back. Target it with a well-placed arrow and the Tallboys will go explodi-bye. Obviously this isn't the stealthiest of options, but you might consider it a risk worth taking just to make the Tallboy disappear, as they're easily the most fearsome opponent you'll face in the game.