The Crimson Binome
Hero
According to narrative convention, falls are very rarely lethal, unless the story is almost over. If someone goes over a cliff, then it's a virtual guarantee that they'll show up again later on, especially considering the difficulty of going down to make sure they're actually dead. That's exactly what I'd expect to happen in one of those new-age story-telling games, like Dresden Files.The way I look at it, what’s the expectation you’d have of a person falling off an 80 foot cliff? Not in a game or even in the real world. Let’s say you’re reading a novel and it happens.
But D&D isn't a story-telling game. It's a traditional RPG. The rules of the game reflect the reality of the game world. Making an appeal to narrative convention would be tantamount to meta-gaming. We're supposed to believe that this could really happen.
So I would consider a fall from 80 feet to be very lethal, generally speaking. I wouldn't consider it to be more lethal than getting stabbed with a sword, or shot with an arrow, or being set on fire, though. All of those things are very deadly. While it makes perfect sense that some random person would probably die from that fall, the fact that I've observed this specific individual withstand superhuman levels of injury in the past means that they aren't some random person. Based on everything I know about this individual, it would be very unusual if they had survived so much, only to be laid low by a mundane fall; which is exactly what the rules of the game tell us.
We already know that the world in discussion differs from our own world in several ways. Even if you restrict yourself to human fighters, a level 3 human fighter is already capable of shrugging off multiple arrow hits without slowing down. It's kind of an unusual premise for a narrative, but that's the cost of admission if you want to play. That's the minimum level to which disbelief must be suspended, if we're going to use this rules. And once we've paid that cost, it doesn't cost anything more to accept surviving a fall from 80 feet.