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. The creature lands prone, unless it avoids taking damage from the fall.
Falling 5e rules
The rules text from The Environment in the SRD 5.1 (the 2014 rules), with the rules around it and the numbers worked out.
Falling damage by height
| Fall | Damage | Average | Most |
|---|---|---|---|
| 10 feet | 1d6 bludgeoning | 3.5 | 6 |
| 20 feet | 2d6 bludgeoning | 7 | 12 |
| 30 feet | 3d6 bludgeoning | 10.5 | 18 |
| 40 feet | 4d6 bludgeoning | 14 | 24 |
| 50 feet | 5d6 bludgeoning | 17.5 | 30 |
| 60 feet | 6d6 bludgeoning | 21 | 36 |
| 80 feet | 8d6 bludgeoning | 28 | 48 |
| 100 feet | 10d6 bludgeoning | 35 | 60 |
| 150 feet | 15d6 bludgeoning | 52.5 | 90 |
| 200 feet or more | 20d6 bludgeoning | 70 | 120 |
The Feather Fall spell slows a fall to 60 feet per round, and a creature that takes no damage from the fall doesn’t land prone.