Slot machine structural characteristics: Distorted player views of payback percentages


  • Kevin A. Harrigan University of Waterloo, Waterloo, Ontario, Canada. E-mail: <email xlink:href=""></email>



slot machine, probability, randomness, virtual reels, gaming regulations, problem gambling


This paper presents a sample three-reel three-coin slot machine game with a bonus for three coins, and a true payback percentage of 85.6% when one or two coins are wagered and 92.5% when three coins are wagered. The player sees the winning or losing combination of three symbols on the payline as well as (a) the physical reels as they scroll by and (b) what is just above and just below the payline at the end of play. An analysis of this game shows that observing the physical reels and what is just above and just below the payline indicates that the slot machine would lose money, and thus the player would make money, as the game would have a payback percentage in the range of 192%-486% if this reflected reality. The paper concludes by discussing the results of the analysis in terms of gaming regulations and problem gambling.






Original Article