a shell game
1. A game in which an object is placed under one of three cups or shells, which are then moved around. The person playing the game must guess the final location of the object. Don't play any of those stupid shell games at the carnival, they're impossible to win!
2. By extension, a method of deception that involves hiding or obscuring the truth. Primarily heard in US. The appliance salesman played a shell game and switched the refrigerator I agreed to purchase with a used model. A Ponzi scheme is a type of shell game that always fails because it relies on money from new investors in order to pay old investors.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
a shell gameAMERICAN
If someone is playing a shell game, they are deliberately deceiving people, usually by changing things or pretending to change things, in order to gain an advantage. At the same time, O'Leary was playing a shell game, moving money from one account to another to satisfy debts. Independent financing — with its soft money schemes and local tax breaks — is at best a shell game. Note: The shell game is an old confidence trick. An object is hidden under one of three cups, which are then moved out of their original order. The victim bets on where the object is, and typically gets it wrong. The trick may have become known as the shell game because it was originally done with walnut shells rather than cups.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012