It's a fantasy role-playing game.

DM: You are Nott the Brave, a goblin rogue . You are the member of the famous group of adventurers. Previously, you and Yasha kill one before she can fly away holding one of the crew. Caleb casts Fear and forces two more to flee.
DM: That'll do it. (cheering) And all out of hit points. So (arrow sound) the second one, you watch as it goes (pained sounds) and it begins to just careen down towards the edge of the ship.
Player: Oh no!
DM: It's about to slam-- we'll see, there's a percentage chance here.
Player: Ooh, percentage dice?
DM: I'm going to roll a percentile dice to see if it hits either on the deck, or over the edge. No, it hits on the deck.
Player: Oh, nice.
DM: 50% chance of either. It crashes in to the other guy, slams in to the side of the railing, manages to pull free and catches up with the other guy as they both run inside the ship. At this point, the other harpies now are just--
