The basic information to know about slot machines. EGM is the short form of the Electronic Gaming Machine. The optimal play is the payback percentage which is based on the gambler by the use of optimal strategy skill in theskill based machine. A player is playing the video or computer game and the manufacturer is able to offer more interactive elements to the player with advanced bonus game with advanced graphics. This is why it is impossible for a gambler to win in the long term. He is capable to play 24 hours and there will be no need to pay anything. Sometime it can also award the coin prize but most of the time, the prize will be small but it will be paid together with the amount won during the free spin. Hopper fill slip: it is the document which is needed in recording the replenishment of the coin on the coin hopper when it gets depleted because of paying the players.