This mod makes combat faster, deadlier and more realistic by increasing how much damage everyone take - both you and NPCs.

The damage multiplier changes according to the difficulty.

Novice: x1.0. This is the equivalent of playing on standard Adept difficulty.
Apprentice: x2.0
Adept: x3.0
Expert: x4.0
Master: x5.0

Special thanks to Phitt, this mod is based on his work. If you wanted to change only the amount of damage you take, but leave your damage dealt constant, try Phitt's "Custom Difficulty" mod:

http://www.skyrimnexus.com/downloads/file.php?id=4981