Slot machines occupy more space on the gaming floor of casinos than any other form of gambling by far. But did you know that the first slot machines were manufactured nearly 120 years ago in San Francisco?  Those first slot machines had three mechanical reels that were spring mounted and which had as many as 20 different kinds of symbols reproduced on the wheels. Players set the machines in motion by pulling on a lever (hence the nickname “one-armed bandit”) and each of the symbols had an equal chance of rolling up. When there were 20 symbols, the chances of the jackpot were one in 8,000.

Slot machines did not undergo a significant chance in their basic structure until the 1970s and 1980s when the number of reels increased. Not coincidentally, this meant that players’ chances of hitting a jackpot also decreased. However, the upside was that jackpots were usually much bigger.  The next change was the development of the virtual slot machine and video slot machine. They didn’t have real reels anymore, and because their reels were “virtual” the numbers of symbols went up into the stratosphere. They were no longer limited by physical constraints.

RNGs Determine Outcomes & They’re Random

Although virtual and video slot machines don’t have actual reels, they rely on random number generators (RNGs) that figure out odds as if the reels existed. The computer in the slot machine calculates the position of the symbols on the non-existent reels and then translates that into a rendition that the player sees on the screen. The computer also calculates whether the player is a winner.  The advantage for the House is that each casino can set its own odds and payout percentages. It is not necessary to get a new machine, or to spend a whole lot of labor altering an old machine. The casino operator simply opens the software and changes percentages in sometimes hundreds of slot machines simultaneously.

Payout percentages are calculated over time. Results in a window of time may possibly deviate from the norm, even though they will average out over the long run. Besides the payout, which might be 99% (i.e. the House keeps one penny for every dollar bet) the casino also decides whether the slots are a low hit or high hit slot. A slot programmed to be a low hit machine, will provide jackpots that are rarer, but also larger.

Post contributed by Breton – an expert in the online slots realm.