Editing Sorcerous Arts:Rules Modifications (section)

===Being Disabled===

In standard d20, characters are disabled (can only take a single move or attack action each round, lose one hit point if they do so) only when they hit 0 hp. We will be playing where characters are disabled at either one fifth (for heroic) or one third (for normal) of their hp total, rounding down. Thus, our above example 3rd level Rogue with 24 hit points would be disabled when they reach 4 hp.