How to play Mafia with 7 players?

To play Mafia with 7 players, assign roles of Mafia, Detective, Doctor, and Townspeople. The Mafia members secretly choose a victim each night, the Detective tries to identify the Mafia, and the Doctor can save one person from being killed. During the day, players discuss and vote on who they think is Mafia. The game continues until the Mafia are caught or outnumber the other players.