Journal of Gambling Studies

, Volume 31, Issue 2, pp 423–439 | Cite as

Modern Multi-line Slot Machine Games: The Effect of Lines Wagered on Winners, Losers, Bonuses, and Losses Disguised as Wins

  • K. HarriganEmail author
  • M. Dixon
  • D. Brown
Original Paper


We simulated the commercially available multi-line slot machine game “Money Storm,” including its bonus wins. Our results show that after a specified amount of time (such as 1 or 50 h), when players played a single line, there were marked differences between one player and the next—a few won a lot, others lost far more than average. When playing 20 lines there were fewer big winners and fewer players quickly losing a large percentage of their money. We simulated a Gambler’s Ruin scenario whereby players arrived with $100 and made $1 wagers until broke. Again we saw a reduction in the variability among player as the number of lines wagered increased, fewer players lost their entire bankroll quickly, and fewer players had big wins. The bonus wins in Money Storm contribute approximately 24 % to the payback of the game, and our simulations of bonus wins shows that with 20 lines wagered the players spend approximately 11 % of their time in bonus wins. With one line wagered, there are no losses disguised as wins while with 20 lines wagered the majority of hits are losses disguised as wins. Players using multi-line machines can thus tune the characteristics of the machine gambling experience to match their preferred pattern, though most seem in practice to bet on the most possible lines. Our results serve to inform researchers, counsellors, gamblers and others about how slot machines are designed, and the effect that wagering on multiple lines has on short-term and long-term play, bonus wins, and losses disguised as wins.


Gambling Gambling addiction Electron gambling machines Slot machine 



This research was funded in part by the Ontario Problem Gambling Research Centre. Computer simulations were programmed by Linus Shu.

Conflict of interest

The authors declare they have no conflict of interest.


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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Gambling Research LabUniversity of WaterlooWaterlooCanada
  2. 2.Psychology DepartmentUniversity of WaterlooWaterlooCanada
  3. 3.School of Computer ScienceUniversity of WaterlooWaterlooCanada

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