A house rule for first edition, D&D.

Daniel S. Wall

Whenever a character scores a critical hit, roll a die 12 and consult the chart below. If more than one option is listed for a result, the first option applicable to the situation is the one that counts. If no listed options could apply, then the result defaults to Option O.

Note that some monsters may not be affected by options listed on this table. A goo cannot be subjected to a called shot and some monsters may be immune to stunning, etc. In such cases, the critical hit is meaningless.

Definitions

Ally: Any character, monster, or construct actively helping the principal attacker. This does not include bystanders unless they are actively attacking the same opponent.

Attack (the): The attack which scored a critical hit and landed you on this table to begin with.

Enemy: The target of the attack and/or anyone clearly allied with that target and/or fighting the principal attacker and her allies.

Attacker: The person launching the attack which scored a critical hit.

Target: The individual attacked on the critical hit.

Results

A: Shot counts as a kill shot (i.e. a called shot intended to kill an opponent outright in one shot.

B: Improved Odds of success on a called shot. (If the initial damage qualifies for a percent chance of automatic success, then the called shot is automatically successful. If it does not, then attack qualifies for a percent chance of automatic success anyway.)

C: The attack scores maximum damage.

D: Add 1d12 to the final damage after all relevant multiplications have already been calculated.

E: If possible, the target will bleed for 1 point per round until dead or magically healed. A viable form of non-magical healing has a slight chance of stopping the flow of blood. The chance is equal to the Intelligence of the healer +1% per level of the character (2%) if the healing character has any healing spells or relevant professional skills (such as doctor).

F: Add 1 point per level of the attacker to the damage of the attack for those rolling on the fighter attack chart, 1 per 2 levels for those rolling on the Cleric attack chart, and 1 per 3 levels for those rolling on the thieves and assassins attack chart, and 1 per 4 levels for those fighting on the magic users and illusionist’s attack chart, but every character gets a minimum bonus of  1.

G: The attacker may immediately take an extra attack on the target. If the character dies from the first attack, she may take any relevant actions she cares to take as if she did not attack on that segment after all.

H: The target is stunned for 1 round, as per the rules for a monk.

I: Knock opponent down if possible.

J: Give an ally an extra attack on the target (if that is possible)*. Otherwise, take an extra attack on a different enemy*.

K: Take an extra attack on a different enemy if that is possible*. Otherwise, give an ally an extra attack on the target.*

L: Chance to disarm the opponent attacked. This is calculated by making opposed attack rolls. If the character scoring the critical hit has a disarming weapon such as a trident, she may roll this at a +5.

M: Roll an extra die 6 in damage. Opponent will also move at half rate for an equal number of rounds.

N: Until the opponent activates for their next turn, any attack scored on them will count as a backstab.

0: attacker adds 1d6 to the overall damage.

*            Whenever shifting targets as a result of a critical hit, the new target must be within immediate reach for a melee attack.