When you fall for 15 feet or greater, you will take fall damage when you hit the ground.

At 15 feet fallen, you take 1d6 bludgeoning damage. For every 5 feet fallen beyond that, you take 1d6 additional bludgeoning damage, up to a limit of 1500 feet fallen, dealing 300d6 bludgeoning damage (or an average of 1050 damage).