I read an absolutely fascinating paper recently in SPADA 2, by Richard Swinney and Scott Crawford. It addresses the realities of how long people can live and continue fighting after suffering catastrophic injuries.
The conclusion of the authors is that the human body is significantly tougher than is commonly thought. To whit, they address a few common scenarios, and give a typical case history of a victim.
These include arm amputation, serious head injury with brain involvement, abdominal and thoracic wounds with complete penetration, severed arteries, and pain tolerance for massive lacerations.
In every case, the authors find that the victim of these serious injuries would generally not be immediately incapacitated, and would likely be able to make - at the very least - a few desperate attacks on their wounder, likely ending the fight in a double kill.
They cite that it was common, during the dueling craze in France around 1600, that both duelists would be badly wounded or killed in the fight, or that one would be killed and the other badly wounded.
Some of the more noteworthy case studies they present I will gloss here briefly. The authors stress that these cases are TYPICAL, and not exceptions to the rule. In their research and practice (one of the authors is a military/emergency physician), people are routinely able to continue functioning at or near full capacity for minutes or hours after receiving what would seem like an incapacitating wound.
A man whose arm was severed in a log splitter shut off the machine and fetched his wife. They fashioned a tourniquet for his arm, and drove to the hospital (they did NOT see the need to call an ambulance). Along the way, they stopped to pick up coffee.
A man whose skull was pierced by a hammer, driving bone into the brain, was in complete possession of his senses, and fully capable of fighting - the only effect was he couldn't speak. He could read and write fluently, and had full motor control, and was thinking clearly.
A man whose skull was split open by a halberd stroke (right into the centre of his brain) not only wasn't killed outright, but walked two hundred yards to the physician who dressed his wounds. He died only after some days, but was able to move about, speak, and was in possession of his senses up until his death.
There were two cases of people being pierced completely through the belly with a sword - in one case, the victim removed the sword himself (and was fine after extensive medical treatment - this was in the 1500s) and the other, the victim did not seek medical attention for some hours after the wound, as it did not seem serious to him (this was contemporary).
It's really, really hard to kill someone stone dead in a single cut. The effect of this is that double-kills are actually a very common scenario in unarmoured combat.
I'll be following up on this post with what this might mean for gaming in the next couple of posts.