Damage Mitigation
Summary
Mitigation can be done through stacking AC, but significant amounts of damage mitigation can also be granted through stacking other stats, such as Stamina and Dexterity. Stamina will grant both AC and HP, while having a high percentage of your overall stats dedicated to Dexterity will grant a noticeable bonus to Parry. The chance of parrying appears to be approximately [% of total stats that is dex] * 0.6.
Wearing a shield in your secondary slow, or equipping the warrior epic 2 hander, will prevent your character from receiving critical strikes or crippling blows.
Additionally, some classes will grant an innate damage mitigation bonus to your character. The maximum bonus a character can have is 30%.