Tales of Justice
A character who takes an amount of damage equal to or greater than his Body, Spirit, or Mind from a single attack — regardless of the Current Condition being targeted — is Stunned by that blow, even if the blow does not knock the target unconscious because he neutralized part of its effect through the use of Last Ditch Defense.
A stunned Character may take no Dice Actions during the phase in which he was Stunned, if he has not already taken an action in that phase; and in either case, he may not make a dice action in his next phase. Stunned Characters still receive their full OV, RV, and defenses against any and all attacks made upon them. Stunned Characters may make Automatic Actions at the GM’s discretion.
Stun can also be caused by intentional Knockback!