Monopoly money
From Conservapedia
Monopoly money is a slang term used to define a real currency which has become worthless due to excess printing.
The term comes from the Parker Brothers game Monopoly, where the rule book specifies that if the "bank" runs out of "money" (only a limited amount is provided), the players can "print" their own (i.e. make it out of any paper) to continue the game.
Historical examples of this include the German Papiermark (prior to Hitler's rise to power), the Yugoslavian Dinar, the Zimbabwean Dollar (which has actually printed a $1 trillion note), and the Venezuelan Bolivar.
