We once had a new years party in the theme of prohibition. Everyone dressed as gangsters and molls and they had to disguise their drinks so it looked like something else. I got a roulette and blackjack table in from a hire company who came and conducted the games. We had posters of outlaws like Al Capone on the walls and the room was dressed up like a speakeasy. Then we had a raid by the untouchables just before midnight with guns (toy of course) and everything. It was good fun.