In vanila Skyrim, crit damage is set to half of the base untempered damage, which is very underwhelming most of the time and almost neglectable.

In this mod a critical hit is redefined as a hit bypassing armor which landed on a vital area. Since that's how the game calculate crit damge (it ignores armor). With that definition, crit is reblanced as follows:

• Only standing power attacks will get a bonus chance to crit, it's designed as a deliberate attack that's aiming at opponent's vitals.
• Dagger and crossbows will now do 2x base untempered crit damage, bladed weapons does 1x, blunt weapons does 0.5x. This reflect how well a particular weapon is able to apply a large amount of force to a small area of impact.
• Enemies that have no vitals can not be critical hit, consult the race article to see which ones can't be crit. As a rule, undead, automatons, and massive creatures (their vital areas are too high for the player to reach) can not be crit.
• Dragons and giants have been given special timings during which they can be crit, see David and Goliath article