9. Chaos Events - Dishonored
Arkane games are always subtly keeping track of player behaviour, and most even alter the experience to accommodate the kinds of choices - moral or otherwise - players make on a moment to moment basis.
In the original Dishonored this was kept track of via a chaos meter, which made the game more difficult the higher it went. If you kept this ticking up you'd end up having streets teeming with plague rats and having to deal with more human enemies stationed around maps. And the best way to increase your chaos rating? You guessed it: indiscriminate killing.
Dishonored accommodates a whole bunch of playstyles, and gives you the tools to ghost through levels without being seen by guards, as well as non-lethal weapons to knock out anyone in your path. You also have guns and swords that'll just take heads clean off as well though.
So the choice is yours: you can edge towards the bad ending and encounter tougher enemies (justified in game as being a response to so many people turning up dead), or keep it holstered when you can.