In a game system having a display unit capable of displaying a game screen (100),
an input unit for supplying a signal corresponding to a player's operation, and
a game controller for executing a predetermined game on the screen of the display
unit with reference to an output signal from the input unit, in which the game
controller selects a predetermined number of trump cards (110 . . . 110)
as the symbol to be displayed on the game screen from a predetermined selection
candidate group, controls a dividend for a player based on a combination of the
selected cards (110), and controls a probability of a dividend by adding
or removing at least the joker (110a) as one common symbol which
can be used as a plurality of cards (110) to or from the selection candidate
group, according to the outcome of the game.
