Because casino games are dealt by house dealers, a small disk — called a puck, a buck, or, most commonly, a button — is used as a marker to indicate the player in the dealer position. That player is always last to act. The button rotates clockwise around the table with each hand that’s dealt. The expression “passing the buck” does not refer to dollar bills, but to poker. And President Harry S. Truman, an avid poker player himself, had a sign on his desk in the White House that read, “The buck stops here.”
