There are various stances available in Age of Conan, depending on your class will vary the stances available.

Soldier Stances[]

Defensive Stance[]

You take less damage from all attacks, have a greater chance of avoiding attacks, but lower your damage. Being in Defensive Stance does not drain your stamina, however Actively Blocking / Avoiding Does.

Frenzy Stance[]

This greatly increases your damage, but you take significantly more damage when attacked.

Assassin Stances[]

Assassin stances were removed. Both of the stances are now passive feats in the Lotus and Corruption feat trees.