Mafia 83. Doctor Who: Aliens in London

Some experienced game masters (like myself) use colors to distinguish the factions, which is quite obvious. Here, I've also added names to each faction, and there are win conditions, which should also be clear. Another challenge is that there are two independent mafia factions and one smaller faction playing for the city, which isn't typical for experienced players.

How are the roles assigned? By a random number generator, or does the game master assign them?

Only random assignment, only hardcore.