Patent 7762882 was granted and assigned to Aruze Gaming America on July, 2010 by the United States Patent and Trademark Office.
In the base game, when a winning combination is realized by a plurality of symbols rearranged on a display, a control for holding symbols related to this winning combination and carrying them over to a next base game is carried out, and symbols related to a newly realized winning combination are held instead of symbols already held only in case where a payout amount for the winning combination is greater than a payout amount for a winning combination already held.