Multiline gaming machine

A gaming machine having display means arranged to display a plurality of symbols in a display format having an array of n rows and m columns of symbol positions, game control means arranged to control images displayed on the display means, the game control means being arranged to pay a prize when a predetermined combination of symbols is displayed in a predetermined arrangement of symbol positions selected by a player, playing a game, including one and only one symbol position in each column of the array, the gaming machine being characterised in that selection means are provided to enable the player to control a definition of one or more predetermined arrangements by selecting one or more of the symbol positions and the control means defining a set of predetermined arrangements for a current game comprising each possible combination of the symbol positions selected by the player which have one and only one symbol position in each column of the display means, wherein the number of said predetermined arrangements for any one game is a value which is the product k.sub.1 . . . .times. . . . k.sub.i . . . .times. . . . k.sub.m where k.sub.i is a number of symbol positions which have been selected by the player in an i.sup.th column of the n rows by m columns of symbol positions on the display (0<i.ltoreq.m and k.sub.i .ltoreq.n).