Falling Damage
Falling damage is for my players almost as scary as in real life, now.
I'll never forget in a game about eight months ago the 12th level fighter who jumped out of a 110-FOOT TREE, took 43 damage, got up and joined in a fight with around 70 or 80 hit points remaining. While cool, it was so over the top we are still referring to it, as late as our most recent session.
Now, that 12th level fighter would have around 90 to 100 max hit points, and taking a 60-point fall or so, with a potential to be a 100-point fall, would not be something he did lightly. And that fighter would look at a 500-foot drop and shy away like a level 1 green recruit...