We use this game at camp & we love it, however we call it “Mafia”.
Suzette is correct, in that the cards work, but are not critical. Most of the time we just scratch something on a scrap of paper. Depending on the group size you can change the number of mafia.
Once your group has a good grasp on the game as described in the original message, it’s easy to add a doctor. After the mafia has done their dirty deed and gone back to sleep, the doctor wakes up and trys to save someone. If by chance they save the same person that the mafia tried to “off” then the victim survives. Adding this character adds a lot to the game, because then the Mafia has the goal of nailing the doctor first, and the doctor can choose to be selfish and save themselves every time, and of course never wants to waste their time saving the mafia!!
Try it out a few times and let it evolve to fit your group. Who cares if you call the doctor a medic or anyone anything else !!
At our camp there is a sign near the cabin area (due to the narrow road) that is suppost to say “NO R.V.’s beyond this point, however it reads “NORVS beyond this point. — Obviously this create’s speculation about what norvs are, and this game has become “Norvs vs. Campers” — The townspeople become campers,the Mafia become Norvs, and the doctor either becomes the camp nurse or a prayer warrier !!
Have fun with it. It’s a great time killer/rainy day game.