Barrian is an attack which protects you from enemy physical attacks by erecting a wall in front of your side of the battlefield.
The amount of damage it can withstand varies depending on the individual attacks - rank is a big factor though. A Barrian (A) will withstand more Attacks (E) than Total Losses (S).
Unaffected Attacks Edit
A number of attacks can affect beasts even when the amulet is protected with a Barrian. As a rule, most attacks starting with "Ad" - Ad Slahnit, Ad Murmanite, etc. work regardless, despite Barrian being cast. Not all magic attacks are, however - Maldiard, for example, is affected by the wall.