Statistically, the chances of winning big on a slot machine are slim. There’s no skill involved, no way of upping the odds – and yet the slots remain the top-rated game in casinos nationwide. According to Harrah’s Entertainment/TNS polling data, more than a quarter of the U.S. adult population visited a casino in 2006, and 61% named the slot machine their favorite casino game. Despite the fact that the slot machine is fundamentally skewed in favor of the house, people just can’t stop pulling that lever. The thrill of the possibility – the thrill of uncertainty – drives us on.

The concept of certainty, or even of luck, would be misplaced in relation to today’s slot machines. The advent of the computerized random number generator (RNG) in 1984 introduced the era of digitally-enabled gambling machines, boasting new levels of difficulty and new layers of enticement. When a RNG-enabled slot machine is powered on, it generates a continuous string of random numbers, regardless of use. When the player pulls the lever or presses the “bet” button, the RNG simply stops on the next set of random numbers, each of which corresponds to a specific stop on the reel. Like the old mechanical slot machines, today’s games have a set number of “physical stops.” However, the RNG microprocessor has increased the total number of stops by assigning a multiple of “virtual stops” for every physical stop on each reel. This exponential increase in the number of stops decreases the likelihood of hitting the grand jackpot, but it has also enabled manufacturers to create slot machines with more frequent payouts of smaller denominations.

Paradoxically, it is this system of high-frequency, low-value payouts that keeps people at the slots. The machines are designed to provide immediate sensory stimulation to draw attention to each payout – the flashing of lights and the sound of coins dropping – enticing even the most speculative of gamblers to insert their money and give the lever a pull. This increase in players also increases casinos’ profitability on the machines, enabling them to offer bigger jackpots than ever before. Unlike traditional machines, whose payouts were independent of one another, today’s slot machines are network-connected and can promise winnings in the millions. The “progressive jackpot” system puts a portion of all linked slot machine bets into a combined jackpot, which grows progressively larger until its winning numerical combination is served up by the RNG sequence. Machines of this type allow the risk of loss to be split between multiple casinos while creating the promotional advantage of a multimillion-dollar jackpot for all. The chances of winning remain small, but attainable. In May 2008, a Texas woman won a $21,030,664 jackpot while playing Megabucks at the Palms Casino-Resort in Las Vegas. The promise of this ultimate jackpot, in addition to the immediate stimulation of the smaller payouts, has led to record play in recent years.