Silent Takedown

Sapping, Backstabbing or Choking Out
This is a Rogue Proficiency. Any character may spend the necessary proficiency slots to learn it, but will be thereafter considered dual- or multi- classed, and XP will be split accordingly. The method of takedown learned must be announced at the time that the proficiency is taken.

How it works
Using a light bludgeoning weapon (sap, blackjack, cane. staff, dagger pommel) from hiding, a thief who rolls a successful backstab attack has a 50% chance of knocking out an opponent of equal level with a +/-10% for every degree of level variation.

Some times you just get lucky though, or not. So a critical hit will always succeed and a critical fumble will always fail.

Thus a 5th level thief could always KO a 0 level victim, but could only bring down a 10th level victim on a critical hit.

The victim will remain unconscious 4d6 Turns and must pass a System Shock check or suffer some lasting effect.

Choking Out
If this method is chosen, no weapon is needed to perform the feat and the System Shock check is negated, but the time the victim spend unconscious is cut in half.

Backstabbing & Heavy Weapons
If the thief in question is using a heavy weapon (hammer, mace, flat of sword) as a sap, or has taken the proficiency as a backstab skill, this same formula will immediately drop the victim to -1 HP and they will loose 1 HP per round until treated or dead.