A gaming system is disclosed which comprises a symbol selector arranged to select a plurality of symbols for display at a corresponding plurality of display positions, an outcome evaluator arranged to determine whether the selected symbols correspond to a winning symbol combination by evaluating symbols disposed in defined win lines, and a prize allocator arranged to allocate a prize to a player when a winning symbol combination exists in a defined win line. At least one display position is of different size to at least one other display position and the defined win lines are dependent on the respective sizes of and locations of the display positions. A corresponding method is also disclosed.