SnowleopardVK
First Post
Your friend helps you move, you buy him some beer. Positive Reinforcement.
Somebody tries to rob you in the parking lot, you shoot him. Negative Reinforcement.
Your friend helps you hide a body, you buy him a car. Positive Reinforcement.
Your friend jokes about telling his wife about the body, you smack him upside the head. Negative Reinforcement.
I'm pretty sure those are all positive actually. They all involve giving the other person something (a beer, a bullet, a car, and a smack respectively). The ones you identified as negative reinforcement would actually be positive punishment; giving a stimulation to encourage a behavior to stop.
Negative reinforcement would involve taking away a factor that the players don't like as a reward for doing something the reinforcing person wanted them to do. For example overlooking a rule saying they can't actually kill something in the way they intend to as a reward for making their method sound really cool.