O Death, where is thy sting? Oh, there it is...

Dyson, over on his excellent blog, has just been talking about the WHFRP system of determining damage and death. To summarize, if a blow takes you below zero hit-points, you get to roll a d20 (+ however many HP you are below 0) for Nasty Critical Damage which may leave you mangled or dead. I really like it, conceptually, and I think I may adopt it in preference to the HP/CON damage split I'm using at the moment. Reposted here, straight from Dyson's blog, is the Grievous Unpleasantness Table:
Effects of Mighty Blows (d20 + points below zero HP)
1-4:Merely a flesh wound! Continue fighting with a -2 penalty on attacks and saves.
5-7:Oof! Strike to the groin, head or other painful blow stuns the character for 1d3 rounds, and suffers a flesh wound as above
8-10:Crushing Blow! Character is stunned for 1d6 rounds, suffers a flesh wound, and must save versus petrification/paralysis or be rendered out of the fight – unconscious or otherwise crippled until healed.
11-14:Incapacitating Strike! Character is rendered unconscious or otherwise crippled and out of the fight until healed. Further, a saving throw versus death is required to prevent the obvious side effect of permanent and immediate death.
15-18:Deadly Blow! The character is dead.
19-20:Mangled! The character is dead, and body parts are missing, thrown around and otherwise mangled.
21+:Splatterfest! The character is not only dead, but is grossly dismembered and mangled beyond recognition.

For monsters and NPCs, just make a simple save versus death when reduced to damage from 0 to -5. If the save is successful, then the critter remains conscious but fights at -2. If the save fails, the critter is unconscious, if the save is a 1, the critter dies. If struck to -6 to -10, the critter is unconscious and dies if it fails a save versus death. At -11 and below, just kill the critter.
1-6: Flesh wound
7-11: Oof!
12-15: Crushing blow
16-18: Incapacitating strike
19: Deadly blow
20: Mangled
21+: Splatterfest
It occurs to me that it could easily be used as a standard combat Critical Hit system as well as for below-0-damage, though I'd probably run it in that case using a d12 rather than a d20 to avoid insta-death rolls; they're no fun for anyone. Or possibly I'd jiggle the numbers a bit to weight the chart more towards the broken-but-not-dead end, as shown here to the right:

This distribution only has a 10% chance of instant death, compared with the 30% in Dyson's chart, and some may see that as being soft, they may call me a big pussy, but I don't really care. If you get walloped again once you're down below 0hp, you're probably going to die or be horribly crippled anyway.

Morris CS9 Armoured Car (15mm)

Not many of these came back to the UK after Dunkirk, but the Morris CS9 was a fairly common reconnaissance armoured car with the BEF in 1...