The evolution of the slot machine industry from computerised machines to video slots and the increasing popularity of online casinos and mobile gambling open a world of opportunities for game designers to develop new types of game routines. In this new setting the potential of increased, even unlimited, player interaction arises. Game designers must embrace the change and develop innovative games that make the most of it. Attractive game ideas are needed that will catch the interest of the players by offering them new and exciting possibilities, yet not too new and different that the players are alienated. Succeeding in attracting player attention and interest is important because of the size of the industry. In the UK, for example, gambling makes a significant contribution to the economy with an estimated expenditure of