It's a fantasy role-playing game.

DM: You are Keyleth, a half-elf druid . You are the member of the famous group of adventurers. Previously, you restrains Daxio further with a vine. Grog shackles Daxio with manacles and pulls him out of the cell, smashing him against the opposite wall.
DM: All right. Second one-- natural one on the second roll. Metal's clinking against the wall. Third one-- is going to be a 17?
Player: 17 is exactly what he needed.
DM: 17 does hit, all right. It's going to try and trip-attack you, so you take as this third strike-- 12 points of slashing damage. And make a strength saving throw.
Player: 15.
DM: 15. With that, slams it around and hits you right about the kneecap. The blade hits the armor and it guards most of it, but the sheer force of the impact knocks you off your feet and you land face-down on the ground, in front. With that, Daxio uses the momentum of the strike to and use the action surge ability. He's gonna do three more strikes against your now-prone self. With disadvantage, and you're prone so each attack has no disadvantage against you.
Player: Yeah.
DM: That's a natural 20.
