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Double Diamond Slot Game Review

In 1990 International Gaming Technology (IGT) released two electro-mechanical slot machine games to Las Vegas-style casinos. These games, Double Diamond and Red White Blue, took land-based slotgaming by storm. Both games are still in play more than 25 years later. When people discuss the most popular slot games of all time Double Diamond is usually mentioned in the top few games bymost long-time players.

The basic machine design was intended to facilitate many different games. Although it used three physical reels like traditional slots the results of any spin were determined by an on-boardrandom number generator which picked the positions on the physical reels where the games would stop. This design allowed the game to pay a remarkably high theoretical return to player in the areaof 95%.

As slot machines go, Double Diamond was deceptively simple and yet randomly generous.

The machines could be configured to handle any level of coin from pennies to quarters to dollar tokens to five-dollar tokens, etc. The most popular version of the game was the dollar-token. Theoriginal game accepted one or two coins with separate pay tables for both coins. The two-coin pay table introduced a local jackpot, sometimes just a top prize, sometimes a progressive prize.

IGT also set up banks of Double Diamond machines that shared progressive jackpots and even added an option for a third coin. Some people distinguish between “classic” Double Diamond (two coins)and “updated” Double Diamond (three coin) but there was never any official distinction in the names of the machines. On the other hand, IGT extended the Double Diamond game into new variantssuch as the Triple Diamond.

Game Reels

The game features five visible stops on the playing reels.  The three reels spin past their own glass windows and they can stop with a symbol on the pay line and blank spaced immediatelyabove and below it or they can stop with a blank space on the pay line and symbols immediately above and below.

Unlike many later five-reel games, Double Diamond did not have a left to right or right to left rule. All you needed was a single Cherry or three symbols that matched any of the winningcombinations in the pay tables.

Other Versions of the Game

In 2014 IGT released an online version of the venerable game that upped the stakes considerably. At least in free play mode the minimum bet is $100, which would be a staggeringly high amount towager when the game was first released.

The simple programmability of the machine made it easy to switch out games. All a technician had to do was replace the reels, change the chip, and replace the pay tables display in the top partof the cabinet. And you had an entirely different game played with three reels and five stop positions. The most frustrating part of the game was the coin hopper, which could jam and – on agood run – simply become empty.

A common sight in casinos with a lot of these games was to see a crew shut down the machine so they could fill it with more tokens or coins. Players would stack up their racks of tokens (100per tray) beside them as they emptied the machines hour upon hour. A good system consisted of having one person play for a while and then be replaced by a partner. The first player would takemost of the trays and cash them in, take a quick break, maybe get a snack, and then go back.

But winning was never guaranteed. Players used to speak of “buying the jackpot”. More people failed than succeeded. You might spend several hundred dollars before you could even get back tobreak-even point. The game was not only randomly generous it was randomly greedy.

The early machines came with the classic pull handle on the side, making these games one-armed bandits.  Although you can still find older machines with pull handles in a few places mostplayers are now more comfortable just pressing the Spin button.

Rules of the Double Diamond Slot Game

The original game only has one pay line. Any other game with multiple pay lines is a later generation variant. Because there are only three reels the order of symbol alignment does not matter,with on e exception. Any Cherry symbol even by itself pays no matter what else is displayed on the other reels.

The Double Diamond emblem is the game’s Wild symbol. It substitutes for everything and even doubles the value of the prize it contributes to. Two Double Diamond symbols lining up with any othersymbol paid four times that symbol’s normal prize. And three Double Diamond symbols paid the highest prize for 1 coin, a fixed jackpot for two coins, or a progressive jackpot for three coins.

Other Symbols in the Double Diamond Slot Game

The remaining symbols consisted of a Single Bar, Double Bar, Triple Bar, and a Red 7.

The lowest paying Bar combo consisted of one of each of the three bar symbols. After that you had to get three of a kind or (two of a kind) and a Double Diamond.

The Red 7s only paid in combinations by themselves or with Double Diamond symbols.

Some later variations of the game might add more symbols, such as a bar with a 7 in it. The online game just uses the basic symbol set.

How to Play the Double Diamond Slot Game

Most slot gaming experts will tell you there is no strategy involved in slots, although that is less true of the most modern slot games that involve interactive features. However even the classicDouble Diamond slot machines could be played according to a simple money management strategy.

The general idea was to roll your money up from, say, $20 on a quarter machine to the point where you had a few hundred dollars. You might lose your $20. Remember this is all random and there areno guarantees you’ll come out ahead. Still, if you had $300 or more you could try your luck on the dollar version of the machine.

If you had about $2000 or more you could try your luck on the $5 machine.

Gamer experiences and opinions broke down after that point. Some players refused to “go down” to a lower coin denomination as long as they had money in the big machines. Other players nursedtheir bankrolls through tough times hoping to build them up again.

Because the games allowed you to play one or two coins on standard versions and three coins on progressive versions you could play conservatively by reducing the number of coins you played.This did not make it more likely that you would get three Double Diamonds. It simply made your money last longer.

With the free online version of the game you only have one coin denomination, $100, so you cannot vary the amounts of your wagers. Unlike multiline slot machine games, varying the amount ofyour wager is more effective on a single line slot machine because you’re not changing your chances of winning by reducing your wagers you are simply changing how much you can win.

Because the chances of getting three Double Diamonds are exactly the same every time you spin the reels (not very good but relatively unchanging) you could, on a three-coin machine, drop downto play single coins until you built up your bankroll again and then increase your bets later. The key was keeping your money in the machine long enough to get a big payoff.

Payback Percentages Explained

Of course, with a 95% theoretical return to player the casino was counting on players to run out of money or time and go home before they got back to the break even point or even moved ahead.


With the online version of the game there is almost no reason for anyone who doesn’t have money to burn to play it. The single denomination restriction undermines the clever money managementstrategy above. You have to deposit enough money, probably several thousand dollars, to ensure you can play long enough to get a good prize. The online casino’s chances of keeping your money aremuch better.

Still, you could win some nice prizes. Three triple bars pay 40 times the bet amount, or $4000. If you get on Double Diamond and two Triple Bars you’ll be paid $8000. Two Double Diamonds and aTriple Bar pay you $12,000.

The Double Bar combo pays 25 times your wager. So one Double Diamond increases that to 50 times your wager and two Double Diamonds increase the prize to 100 times your wager.

These are heady numbers. All you really need to stay in the game is a constant supply of Cherry symbols and mixed bar combinations. If that is all you get you’ll eventually lose your money butwith enough spins you have a reasonable expectation of getting a prize with a Double Diamond.

A Single Bar + Double Diamond + Single Bar combination pays 20 times your bet. That gives you twenty more spins.

However, if you are not careful you end up overthinking the game. Remember, there is no strategy for spinning the three reels. The outcomes of the spins are determined by a random numbergenerator. The game uses three “virtual” reels consisting of, say, 10 or 20 slots with a mix of blank and non-blank symbols. There may be only one Double Diamond symbol in each virtual reel. Therandom numbers tell the game which slots will appear on the pay line next. So you click Spin, the machine grabs three random numbers, and uses each random number to move a counter that manypositions on a reel, wrapping around if it gets to the end.

If you cannot vary the coin amounts you are simply betting on random events with no flexibility.   That is not a strategy it’s just pure, old-fashioned gambling. You pay your money, youspin the reels, and you see what happens.

As slot games go Double Diamond may still seem appealing for nostalgic reasons. Many experienced slot players may just want to relive old jackpot moments. That’s a dangerous feeling but if youhave the money to lose you may enjoy a few spins. You could also win.

Some players may want to experience that old time slot experience their elders used to talk about. The online game is an expensive tour of the old days.

Why You Will Love This Game

What makes the game addicting, though, and what long-times players remember, is that long series of bell rings when the game tallies up a nice prize. It counts up to the total in singleincrements of your wager: Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding!  When you spin up a 7 and two Double Diamonds, for example, you will hear 320 dings. That’s when the old timeplayers lit up a cigarette, sat back, and took a deep breath.

A 320 times bet prize might get you back to where you started, or close to it. If nothing else you know that in the worst case scenario it gave you another 320 spins. At least with the onlinegame you don’t have to scoop up filthy tokens and go wash your hands. You can take a quick break, reassess what you want to do, and go on about your business. But once you hear that long sequenceof bell rings for the first time you’ll understand why Mom, Dad, and the Grandparents spent endless hours at the casino putting coins and tokens into these machines.

Our Thoughts:

They wanted to feel that “gambler’s high” one more time before going home. You will too. Just remember to gamble responsibly. After all, it’s just a game.

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