From Before I Play
- You have a LOT of leeway in terms of killing people before you go into "High Chaos". Don't be afraid of going loud once in a while and don't reach for the reload button every time you're caught while sneaking around.
- Making a kill in the very first combat scenario will ruin your chance at a no-kill run if you want the achievement, even though it feels really natural to do so.
- If you're going for no-kills, be really careful about setting down unconscious people near stairwells, and railings, and such. They loooove to slump over the side and fall on their heads, and then die, and count as a kill you made, and ruin your run.
- Aside from obvious scripted deaths, anybody that dies counts as your fault. So if you knock out somebody and they get eaten by rats, that's a kill. If some poor plague-ridden idiot follows you out into the open and then gets shot by healthy people, that's also on you. That said, you can kill quite a few people before there's storyline and ending repercussions, so don't worry about it too much unless you're trying for the achievement for not killing anybody.
- Bone charms are randomized, so you might be able to save scum your way to better ones, but I'm not sure if they're set in stone when you first load the level or if you collapse the wave function when you loot them.
- Any bone charm or rune stone that the heart shows you an indicator for can be gotten only on whatever mission you're currently on. Some times you'll revisit a map later in the game, but it'll have new runes and charms and you'll have lost the chance to pick up anything you missed the first time around.
- If you think there's any chance that you might want more mobility at all, buy the improved teleport power and the athletics power. You can get to a lot of things you otherwise couldn't and get to the things you could normally reach a hell of a lot easier with the bigger jump height and farther teleport upgrades.
- The initial teleport power is the best power in the game. It's a silent way to teleport from one spot to another and can be used when carrying bodies or setting up attack runs. Enemies have much less in the way of vertical sight range than you'd think, even being on a rooftop makes you very hard for them to spot. Warp down to just behind a guy, strangle him, grab his body, warp back to the rooftop.
- Following on from that, leaving dead bodies in odd places can help prevent deaths from rat swarm. Up on vents, in trash containers, wherever. If a rat can't get to it, it's all good.
- Holding 'use' while strangling someone will automatically loot and pick up the body in one go.
- Your other stock power should probably be Dark Vision, which lets you see people through walls and see their vision ranges. If you let it run for its entire duration, it won't even cost you any mana - it'll all be recovered by the time it's done.
- The game does respawn guards in some areas. I'm not sure whether there's a limit per mission or if it requires them to get eaten or not, but I've had some very safely stashed unconscious guards suddenly have their corpses disappear and enemies back in their places. On the other hand, I grenade'd a bunch of guards indoors and they stayed dead the entire mission.
- Get Blink 2 right away. Really. Even fully upgraded, it won't feel like enough until you master its use, and by then it's such an obvious part of the game that you'll balk at Blink 1's range on your second playthrough.
- Look up. A lot. I kept this in mind my whole first playthrough and still missed some stuff. On that note...
- It's okay to miss stuff! If you like this kind of game, you'll play through it more than once. Nothing saps the pace more than practically pausing the game for an hour to explore every nook and cranny and explore every item. I'm that kind of person with my games, but with this one I forced myself to pick a path and rarely deviate. It was infinitely more rewarding not knowing what cool path I was missing, making the second playthrough that much more invigorating. I definitely took my time to explore things, but I kept pacing in mind and went with how I'd imagine it's "supposed" to be done and found it enjoyable each and every time. Again, probably a minority here, but I wanted to throw that out there.
- It's okay to get caught and fight. The game encourages it with a ton of lethal options. I recommend you live a little bit on your first playthrough, just to enjoy what the game really has to offer without restricting yourself and possibly hindering the gameplay. Summoning plague rats and throwing grenades can be mighty satisfying in the hardest of situations.
- Blink is much more restricted vertically than horizontally. If you put runes into the Agility upgrade, you can do a double-jump by holding A, and that could very well let you Blink higher up at the peak of a jump, or even further across a horizontal distance if you run and time a big leap really well.
- Dark Vision 2 lets you see everything, including items like coins and elixirs. It's a really nice ability, but it honestly can feel sort of game-breaking at times. Some posters compared it to detective vision in Batman: AA. Take a note of this and just decide if you want it based on how hard you want the game to be. If you're aiming for a more difficult experience, pass on the second upgrade.