The answer is not terminal velocity. That happens a considerable distance after this.A fall from a great height is one of the most common hazards facing an adventurer. At the end of a fall, a creature takes 1d6 bludgeoning damage for every 10 feet it fell, to a maximum of 20d6.
This came up in game when a player whose PC was a barbarian came to gorge 1,500' deep and said, "Yeah, I'll just step off."
I asked if they were committing suicide, because this was going to kill the PC. "Nope," the player replied, "The barbarian will survive the fall."
I stated unequivocally the PC would die - yes, I was aware of the rule - yes, I guess this is a ruling outside the rules, and therefore, a house rule that was unannounced. However, I countered, the player was exploiting player knowledge of the rules to benefit his PC.
So, that's where this question comes from - what purpose does the limit on falling damage serve? What am I missing?
I do remember the falling damage rules debates from the early Dragons and the subsequent ban on articles and letters on falling damage. Just reviving an old D&D tradition: Let's debate falling damage!