It's a fantasy role-playing game.

DM: You are Beauregard Lionett called Beau, a human monk . You are the member of the famous group of adventurers. Previously, Fjord wanted to immediately head towards the orb, but the rest of the party wanted to investigate Vandran's cabin further. Caduceus determined the creature that left claw marks was the same one that forced the box open.
DM: Oh, got you. So it would be 20 feet because you round down in D&D unless it specially says otherwise. So you'd be just out of range.
Player: Then let me spend a ki point to do Step of the Wind.
DM: All right, that'll get you the distance you need there.
Player: Which sucks, but that's okay. Then I'm going to attack.
DM: (singing) Do it!
Player: Just jam my staff into its face. Not too bad. 22.
DM: 22 hits.
Player: Okay. That's good. Ten.
DM: Ten points of damage. You have advantage on that attack, by the way, because of the Guiding Bolt.
