Introduction
When it comes to gambling, the easier a game is to understand the worse the odds usually are. This is certainly the case with slot machines. Playing them is as easy as pressing a button. However, between the high house edge and fast rate of play, there is no quicker way to lose your money in a casino.
Before going further, let me make clear that this page addresses the way slot machines work in most parts of the United States and the world. However, some parts of this page do not apply everywhere. For example, I state that slot machines have a memory-less property, where the odds of every spin are the same. In some places, like the UK, some machines in bars, called “fruit machines,” have a mechanism that guarantees a certain profit over the short run, which causes the game to go through loose and tight cycles. These games do not have the usual independence property of the major slot makers.
How They Work
Whether you’re playing a 3-reel single-line game or a 5-reel 25-line game, the outcome of every bet is ultimately determined by random numbers. The game will choose one random number for each reel, map that number onto a position on the reel, stop the reel in the appointed place, and score whatever the outcome is. In other words, the outcome is predestined the moment you press the button; the rest is just for show. There are no hot and cold cycles; your odds are the same for every spin on a given machine.
Slot machines are just about the only game in the casino where the odds are not quantifiable. In other words, the player doesn’t know how the game was designed, so it is difficult to look at an actual game to use as an example. So, to help explain how they work, I created the Atkins Diet slot machine (link). It is a simple, five-reel game with a free spin bonus round, much like IGT’s Cleopatra game.
For information on how it works and all the odds, please visit my Atkins Diet par sheet.
For a more complicated example, featuring sticky wilds in the bonus, please try my Vamos a Las Vegas slot machine.
For information on how it works and all the odds, please visit my Vamos a Las Vegas par sheet (PDF).
Odds
The following table shows the casino win for Clark County Nevada (where Las Vegas is) for all slots for calendar year 2012. They define “slot” as any electronic game, including video poker and video keno. I’ve found video keno to be about equally as tight as reeled slots, but video poker has a much higher return. So, the return for reeled slots should be higher than these figures.
Clark County Slot Win 2012
| Denomination | Casino Win (pct) |
|---|---|
| $0.01 | 10.77% |
| $0.05 | 5.96% |
| $0.25 | 5.74% |
| $1.00 | 5.64% |
| $5.00 | 5.51% |
| $25.00 | 3.97% |
| $100.00 | 4.73% |
| Megabucks | 12.89% |
| Multi-denomination | 5.32% |
| Total | 6.58% |
Source: Nevada Gaming Control Board, Gaming Revenue Report for December 2012 (PDF, see page 6).
Most players play penny video slots. Based on past research, I find the house edge on those to usually be set from 6% to 15%. In general, the nicer the casino, the tighter the slots.
Advice
While there is no skill to playing slots, there is some skill in selecting which machine to play and ways you can maximize your return. What follows is my advice, if you must play slots at all.
- Always use a player card. Slots may be a lousy bet, but the casinos treat slot players very well. A $1 slot player will probably get comped better than a $100 blackjack player. Of course, don’t play for the reason of getting comps. You’ll give them a lot more than they’ll give you.
- The simpler the game, the better the odds. The fancy games with big signs and video screens tend to not pay as well as the simple games. However, slot players always tell me the fancy games are more fun.
- The higher the denomination, the better the odds. For that reason, it is better to play one coin per line on a 5-cent game than five coins per line on a 1-cent game.
- Don’t forget to cash out and take your ticket when you leave. It is easy to forget after hitting a jackpot.
- Try to play slowly and as little as possible to get your fix.
- In some games there is a skill feature, like Top Dollar. In such games, advice is usually offered, which you should take.
