“Whatever happens, I’ll send the results to Dragon Magazine!”

Delta’s D&D Hotspot claims to focus on “Math, History, and Design of Old-School D&D”, so it isn’t surprising that Delta has revisited the great falling war of 1983-84.

What is surprising is the data that Delta provides. After a lengthy analysis of the participants in the war, Delta adds:

The real-world statistics of falling mortality are expressed in terms of “median lethal distance” (LD50), that is, the distance at which a fall will kill 50% of victims (who are presumably normal adults). Smith, Trauma Anesthesia, p. 3, asserts that LD50 is around 50 feet (4 stories). Wikipedia asserts that LD50 for children is at a similar height; 40-50 feet. Dickinson, et. al., in “Falls From Height: Injury and Mortality” (Journal of the Royal Army Medical Corps, 2013) notes that LD50 varies greatly by injury type: about [34 feet] for those who land on their head or chest; about [73 feet] for those who do not.

Fifty feet is a long way, and I don’t think I would have ever guessed that the mortality rate was only 50% falling that distance. Asked to guess, I’d probably have said 75% to 85% at least. This may be yet another case where real life is allowed to be stranger than fiction. Even more amazing is how much of a difference knowing how to fall makes: raising the LD50 to seventy feet just by falling better sounds like movie reality.

Of course, even not dying there’s likely to be a lot of injuries involved—although seeing the LD50 numbers does make me wonder what the serious injury rate is, and whether I’ve been overestimating that, too—and Gods & Monsters, unlike OD&D has a system for that. As Leland J. Tankersley writes in the comments,

I think the fundamental problem in reconciling reality with D&D-like games is that health in D&D is in some respects binary—you are either dead or effectively so (0 hp or less), or else you are “fine” (1 or more hp, which might be “near-death” in some sense but which doesn’t impair your ability to act in any way. While LD50 may be 50' for a typical human, I feel confident in asserting without evidence that the vast majority of those that are NOT killed by a 50' fall are nevertheless incapacitated (broken/shattered legs, for example).

Because I added injury point rules to Gods & Monsters, it does a little better than OD&D/AD&D on falling damage. Rather than an every ten feet rule, I chose to go with a 10/20/40/80/etc. progression, with each die of damage also potentially causing one point of injury damage. This means that a fifty foot fall only does 4d6 damage instead of 5d6, and four of those will be injuries. And also as a result of having an injury rule, zero survival (hit points) doesn’t mean death in Gods & Monsters: only injuries cause death.

Of course, your average person gaining an average of ten injuries will die. Their health is likely to be 4 or 5, and with a penalty of ten¹ that means the player needs to roll -6 or -5 or less on d20 to survive.²

This is patently impossible.

On the other hand, surviving with one or two injuries—from rolling four or five or six on the 4d6 roll for falling damage, or even slightly higher if this person has five or six survival—is not easy for the average person, but far from impossible. It would mean rolling less than or equal to one, two, three, or four, depending on the combination of numbers, on a d20.

But that may not be enough. I could certainly see going to 20/40/80/etc. progression, that is, 1d6 damage at less than 20 feet, 2d6 from 20 to 40 feet, and 3d6 from 40 to 80 feet, and so on, with a maximum of 6d6 instead of 7d6. At 50 feet, this would still do 3d6; this would still kill the average person more than 50% of the time, but it would also not kill quite a few, and all of those not killed would be seriously injured. They’d have at least three injury, which is a lot. It means a penalty of three on all rolls and, probably, unconsciousness.

I’m not sure; at the moment I’m inclined to stick with the current rules. I would say, however, that “falling” should be allowed as a skill within some fields, such as the Athletic Art or Survival Craft and maybe even Medical Science. Under the current rules this would not reduce injuries for falls above twenty feet, but it would improve the chance of making those be survivable injuries, by improving the character’s roll to not die from them.