It's a fantasy role-playing game.

DM: You are Percival de Rolo, a human gunslinger . You are the member of the famous group of adventurers. Previously, Sylas leaps out of the smoke towards Percy's hiding place, pulls out his large two handed onyx blade and hits Percy twice. Each hit robs Percy of strength and grants a boost to Sylas.
DM: Okay. You feel as each strike of the blade cuts into your flesh, a portion of your body's strength is sapped from it. Your strength goes down by two.
Player: My strength is a negative one.
DM: No, I mean your score. Not the modifier, your score.
Player: Oh, so my strength is at zero, then.
DM: What is your strength normally?
Player: 12.
DM: 12, so it's now ten.
Player: It's now ten, which means my modifier is zero.
DM: You see the energy fill him now.
