A gaming machine 10 has a display 12 and a game controller arranged to control images of symbols displayed on the display 12. The game controller is arranged to play a game wherein at least one random event is caused to be displayed on the display 12 and, if a predefined winning event occurs, the machine...http://www.google.ca/patents/US7070501?utm_source=gb-gplus-sharePatent US7070501 - Gaming machine with free game play
