Sheriff of Nottingham is a game where you play the role of a merchant in medieval times. You and your friends take turns being the Sheriff, whose job it is to stop people from bringing in illegal goods like weapons or contraband. The other players try to sneak in as much illegal stuff as they can without getting caught.
Each player takes turns being the Sheriff and inspecting the other players' goods. If the Sheriff thinks something is illegal, they can confiscate it and make that player pay a fine. But if the Sheriff lets something illegal through, they have to pay a fine themselves.
To make things more interesting, players can bribe the Sheriff or try to bluff their way past with "legal" goods that are actually illegal. If a player can successfully smuggle in the most contraband at the end of the game, they win!