When a character undergoes medical treatment a ref is required in order to do bead pulls, which determine the outcome of said treatment. A white bead means that the treatment has been a success, and a hit is added to the character. A red bead means something has gone wrong with the treatment and a hit is deducted instead. Both red and white beads are returned to the bag once pulled. Depending on player actions refs may add or deduct beads. Additionally some equipment can alter the bead pull by changing the ratio of white to red beads. The starting ratio of beads is 7 white to 3 red. Each bag represents that particular patient. A doctor moving on to treat a new patient requires a new bag.