Death and Dismemberment Table (BFRPG, B/X, Similar)

Basically, when you hit 0 hit points you roll 1d20 and refer to the table below.  If you take any other damage while below 0, you roll again and deal with multiple results.  Characters can be stable but in negative hit points as a result of the effects or further actions taken.  If a character gets to -10 they are dead regardless.  I'm sure I borrowed some, most or all of this from somewhere. 

Death and Dismemberment Table

Roll (1d20)	Result	Effect
1	Instant Death	Described in dramatic fashion; allow for last words as appropriate
2-5	Severed or smashed (1d6 for hit location)	Treat head shots as instant death. Limbs are useless/ missing and torso indicates severed artery or fatal internal organ damage (e.g. punctured lung). Save vs. Death to remain conscious. Death results either way in 2d6 rounds unless healing magic is applied.  This magic will both restore lost HP and prevent death.  In the case of a damaged limb, cauterization or a tourniquet allows a Save vs. Death to survive.  Damage is permanent to survivors (i.e. limbs remain useless).
6-10	Broken Bone                 (1d6 for hit location)	Head shots result in concussion (see below).  Broken limbs are useless but can recover.  Broken torso indicates cracked ribs, can also recover.
11-17	Knocked Unconscious	Out for remainder of the fight, will awake after the battle with 0 hit points.
18-19	Stunned	Stunned for 1d4 rounds, incapable of useful action
20	Adrenaline Surge	Returns 1d4 hit points per hit die (minimum of 1 hp). At the end of the combat, the adrenaline drains away, hit points are reduced to zero, and the character falls unconscious for 2d6 rounds.

Hit location: roll 1d6

1= head

2= dominant arm

3= other arm

4= right leg

5= left leg

6= torso

• Stunned: can at most move 1/2 and perform simple actions, not to include attacking or spell casting.

• Concussion: stunned for 2d4 rounds then -2 to all rolls thereafter until healed to full hit points either magically or naturally.  Tire 5x as quickly

• Severed, smashed and broken arms: arm is useless.  -2 to rolls when using off-hand

• Severed, smashed and broken legs: movement halved, cannot run (can double move for normal movement rate) and tire twice as fast when moving

• Severed, smashed and broken torso: -2 to all rolls in addition to other effects

•  Recovery:  Recovering from a broken bone naturally requires 6+ (1d6 -Constitution bonus) weeks.