Saboteur 2 - How many saboteur cards do you take out for 4 players?
As far as I can see, in Saboteur 2 you never change the available roles based on the number of players. So in your 4 player game, you could have 3 Saboteurs and 1 Geologist, and a completely ridiculous mine in the end. The rules just say "Shuffle the 15 role cards together".