Patent 7651393 was granted and assigned to Universal Entertainment Corporation on January, 2010 by the United States Patent and Trademark Office.
When a player starts playing a game by operating a MAXBET button (e.g. when the bet count is 30 bets) and determined that the currently owned credit count is insufficient to the credit count required for the MAX bet, the current game rate set in a slot machine (the credit count per bet required for betting) is changed to a lower game rate.