Just what are casino dice?

A die is a single six-sided cube with markings on each side that denote the numbers one through six. The numbers are indicated by the use of spots corresponding to the number for that side. A side is a face of a die that contains a spot or spots. Any more than one die are called dice.

Casino dice are different from dice used in board games. Casino dice (also called precision dice) are primarily red and somewhat transparent. Casino dice have to be as square as is technologically possible so as to be fair to both the casino and the players. Dice used in board games are crudely manufactured and always favor the higher numbers (4, 5, and 6) because more material is drilled out of those sides.

Four components of casino dice


Casino dice are made up of four components: the cube, spots, edges, and graphics. The cube is made of cellulose acetate, a special kind of plastic that holds up to the physical stress put on dice by handling and throwing. Casino dice from the 1920’s to the 1950’s were made of cellulose nitrate. This plastic has not fared well over the years and the dice from this period are sometimes crystallized. Crystallization is a change in the plastic of the corners, edges, and sometimes the entire die to a yellow crystallized state. This crystallization occurs from a combination of age (plastic fatigue), and exposure to ultraviolet light.


Next, come the spots. First, the spots on every opposite side should equal to seven. That is, the side with three spots must be opposite the side with four spots, the one spot opposite the six spot, and the two spot opposite the five spot. Spots are made in many different styles: solid, bulls-eye, birds-eye, doughnut, and several more. The spots are filled in with special paint that weighs the same as the plastic that was drilled out for the spots. This insures that each side of the cube weighs exactly the same.

Spot styles from left to right: Solid, Birds-eye, Bulls-eye, Doughnut, Combo Spot, Intricate


There are different kinds of edges used in manufacturing casino dice. The kind used for most modern casino dice is called Razor Edge. The other kinds of edges are: Feathered, Brushed, Slightly Turned, and Heavy Turned. The different edges determine the ability of the dice to grab the cloth of the table and rotate as they are thrown. There are also more edges that are sometimes used in cheating or “gaffed” dice. These other edges offer a greater chance for the dice to be controlled.


Then there are the graphics. These include logos, pictures, lettering, numbers, and symbols. The casino usually puts their name and sometimes the city or location on the face of the one spot. This is because the one spot is the side with the most room. Consequently, a logo or graphic picture is placed on the two side, or in between the spots on the six side.

Dice graphics examples – from left to right: Serial Number, Logo, Symbol, Lettering

Serial Numbers and Cancellation Marks

Much confusion surrounds serial numbers and cancellation marks. What are they, how do they affect the value of casino dice, do the numbers need to match, what if the cancellation is on a logo? Read on to learn about these things and more.

Serial numbers

Serial numbers are numbers imprinted on the dice and are used to indicate a certain issue. The numbers are usually a three or four digit number, although as you can see in the picture below, letters and dashes are sometimes used. The serial numbers are usually put on the six side of a die, but they sometimes show up on the two and four sides as well.

Serial numbers first appreared on casino dice in the 1940’s, but were not used widely until the 1970’s. It is believed that with the corporate takeover of casinos in 1969 that more control and security was needed and so serial numbers became more prevalent on casino dice. Dice from the 1980’s and 1990’s will have serial numbers almost without exception.

Notice in the picture that there are serial numbers on every side but the one side. There are letters, numbers, and combinations of both.

Should the serial numbers match?

There has been much debate over pairs of dice having matching serial numbers. It is believed by some that a pair is not a pair unless the serial numbers are the same. Others seem to think that if the style of dice is identical, the numbers need not match.

I’ve discussed this with most of the biggest casino dice collectors around and what I’ve learned will definitely interest you. The consensus is that if the dice are relatively new (1980 up to today) and are easy to obtain, the numbers should match. If the numbers don’t match the seller should knock a dollar or two off the asking price or be willing to sell just a single. On dice that are twenty years old or older or are very rare and hard to obtain the numbers need not match.

I feel that too much emphasis is placed on matching serial numbers. I agree with the collectors who say that it’s not that big a deal and if numbers don’t match, I always knock money off an order anyway! If you demand matching serial numbers, let me know and I’ll only offer you dice with matching serial numbers.

Dice Punch (Scribe)
Vise Punch (Cancellor)

The dice punch, as you can see, will produce a couple of different cancellation marks. The most widely used is just a stab or two somewhere on the dice or scratching some lines or an “X” into a side. The vise punch (couldn’t find a decent picture, so I drew this one!) is a contraption that twists down and grinds a circle or crescent shape into the surface of the die.

Some places just scratch a side with a razor blade to cancel them. In the 1950’s, many casinos drilled their used dice for sale as keychains and bolo ties in the gift shops. It is the law in Atlantic City that all used dice have to be drilled all the way through the die. That is the reason undrilled dice from A.C. are worth a little more than regular drilled dice. The bosses at other places would sometimes write initials and/or the date on the dice to cancel them.

The side that cancellations appear most is the four side. This is by no means exclusive as dice can, and have been cancelled on every side, one through six. Cancelling does not affect the value of the dice except when the cancellation occurs on, through, or over any logos.

Cancelled dice examples

You can see in the picture that there are many different methods of cancelling dice. The top row shows pit boss initials, pit boss dating, magic marker, bolo tie drill, and Atlantic City drill. The middle row shows vise punching, gouging with the scribe, drilling for a keychain, and razor blade scratching. The bottom row shows different variations of the vise punch.

The Plastic of Casino Dice

For those of you who are really interested in the chemistry and history of casino dice, what follows is a fairly detailed description of the plastic used to make casino dice.

Who invented the plastic used for casino dice?

An American inventor named John Wesley Hyatt (no relation to the hotel family) was searching for a new material to be used as a substitute for ivory. A huge monetary prize was offered to anyone who could come up with such a material. In 1869, Hyatt created what he would call Celluloid, but which really came to be known as cellulose nitrate. He found that by combining nitric acid with cotton cellulose, mixing that with camphor, and treating the result with heat and pressure produced a substance that could be molded into any desired shape. He won the prize and Celluloid was used in the making of billiard balls, combs, dentures, and photographic film. This was the beginning of the modern plastics era, and Celluloid was the only commercially viable plastic for almost thirty years.

Cell-u what?

Cellulose is a polymer (a long chain molecule made up of different molecules, don’t ask me to elaborate, this stuff is deep!) found in wood, cotton, and paper. The fiber found in the pulp of these materials is what is combined with the acids and camphor to produce the plastics.

Cellulose acetate was introduced around the middle 1920’s. Using acetic acid rather than nitric acid in the mixture forms cellulose acetate. Cellulose acetate would come to replace cellulose nitrate in almost every function because cellulose nitrate was highly flammable.

You’ve all no doubt heard of old movies deteriorating because they were filmed with nitrate stock, and maybe you’ve seen casino dice that crystallize and fall apart, that is because they were made from cellulose nitrate. Cellulose acetate is also considered unstable, though not as flammable, and only time will tell if dice made from cellulose acetate will crystallize and deteriorate.


Most plastics are either thermosetting or thermoplastic. These are terms to describe how the plastic reacts to heat. Thermosetting plastics soften with heat but harden with continued exposure. Thermoplastic materials also soften with heat but remain soft if exposure continues. They set when cool and can be reheated many times. 85% of all plastics, including cellulose nitrate and cellulose acetate, are thermoplastic.

Colourants are dyes and pigments added to the plastic so that it is coloured throughout. Titanium dioxide and many iron oxides are used as colourants for the plastic used in making casino dice.

Both cellulose nitrate and cellulose acetate (commonly called cellulosic) can be processed in many different ways. Injection molding, extruded, cast into sheets or film and thermoformed. For casino dice, the cellulosic are cast. In casting plastic, fluid resins are poured into a mold of a rod, roughly square and about three or four feet in length. It is at this time that any colourants are added so that the end colour is achieved. All cellulosics are suitable for normal cutting and machining operations.

Believe it or not, this explanation is a fairly simplistic one. There are many variables such as additives, oxidants, and plasticizers that can affect the final product that are casino dice. These things are way too complicated for me to understand, let alone explain in an intelligent way. I only flunked one subject in school and it was chemistry!

Cellulose nitrate was used to make casino dice from about the early 1920’s until the early 1950’s. These nitrate dice are deteriorating and crystallizing all the time. The switch to cellulose acetate was made because nitrate was so flammable. When the rods were cut, using a mechanical saw, the shavings fell to the ground beneath the saw. If an errant spark were to fall on these shavings, KABOOM!

A mercury-based paint was developed for the spots on the dice around 1950. This paint did not adhere well to the nitrate plastic and many times a spot or spots would just pop out while the dice were being thrown. Not something you’d like to see when betting your money on the outcome of a roll. So cellulose acetate was used as the plastic for casino dice. The mercury paint adhered much better and the flammability is much less than cellulose nitrate.

The dice pictured below are all made from cellulose nitrate. You can see the varying degrees of deterioration, from a missing spot to crystallized corners to crystallized edges, to total crystallization and decomposition.

There is a very disturbing phenomenon that occurs with dice made from cellulose acetate. In the jargon of the film industry, it is called the “vinegar syndrome”. This vinegar syndrome is actually a chemical reaction that occurs when cellulose acetate begins to break down. The process is also called deacetylation and is caused by the acetate ion reacting with moisture, which forms acetic acid and produces a strong vinegar or ammonia smell. If you keep your dice collection in cigar boxes and have noticed this odor upon opening a box, then you have dice that are decomposing. Unfortunately, once this reaction has started, it cannot be stopped. What’s worse, dice that are affected by deacetylation can cause any dice nearby to start the decomposing process.

I used to believe that only dice made from cellulose nitrate caused this syndrome, but I was mistaken. The cellulose acetate dice are the culprits of the vinegar syndrome. The crystallization that occurs with cellulose nitrate dice is caused mainly by exposure to ultra violet light and, so far, has not happened to any acetate dice.

What generally happens is this; you have dice stored in boxes (cigar, plastic, whatever) and the enclosure creates heat, which causes moisture in the air within the box. This moisture reacts with the acetate in the plastic of the dice to form acetic acid, thus creating the strong odor. The cycle is self-sustaining because the reactions cause more moisture that reacts with more plastic.

Another by-product of this process is what I call the “imploding” of casino dice. Dice that seem to implode appear to warp and contort their shape and look like all the moisture is sucked out of the cube. They may even turn a black color and will (mostly, but not in all cases) have the vinegar smell. This has happened only to cellulose acetate dice (so far) and I believe it happens because of deacetylation.

Examples of acetate “imploding” (die in the middle is perfect for contrast)

So, cellulose nitrate dice crystallize and cellulose acetate dice stink and decompose. What’s the use of collecting casino dice in the first place? Take heart, there are ways to combat these chemical evils and ways to prevent them from occurring in the first place.

The sniff factor

The best way to discover if any of your dice are suffering from deacetylation is the sniff factor. If you smell a strong odor among your dice, pinpoint which ones smell and put them all together, away from your collection. These dice will definitely decompose and become worthless. What you need to do is preserve these dice so that you can have some sort of representation for the future. I prefer scanning or photographing the dice and storing them digitally, but a photocopy will suffice. Once preserved for posterity, you can retard the decomposing process by altering the storage conditions of your collection.

Take all your decomposing dice and store them someplace that won’t get above 70 degrees, gets little or no sunlight, and has very low humidity (20 – 40%). If you can, store the dice in an airtight box. What you’re trying to do is not perpetuate the conditions that create moisture.

Help for crystalised casino dice

For dice that are crystallizing, I recommend preserving the dice digitally (explained above), and then treating the dice with a clear lacquer. I have used a clear nail polish lacquer for years to preserve my crystallized dice, and the results have been very good. The crystallization has not worsened, and the dice, once treated, can be handled and viewed with greater confidence.

The main tips to remember when treating your dice is to use the lacquer sparingly (it does not take much to lightly cover each die), use a dabbing stroke on all logo’s (swiping across a logo may smear and ruin it), and let them dry overnight before handling. It is a good idea to store any dice that are crystallized in the same conditions described above for acetate dice, but not directly with your acetate dice!

There is a product that the film industry uses that is said to prevent or at least slow down the vinegar syndrome in film. The product is called a molecular sieve and is a semi-permeable packet filled with a zeolite desiccant. This sieve absorbs acids, moisture, oxidants, and solvents that are generated by acetate. This, in theory, prevents those things from reacting with the acetate and may prevent the degradation process. This technology is fairly new to the film industry and no long-term studies on the effects of the molecular sieve have taken place.

I am in the process of experimenting with the molecular sieve in regards to casino dice. I feel that this may be a very important tool in the preservation and storage of casino dice collections. If any cellulose acetate dice can decompose, then it stands to reason that these sieves should be used in the general storage of casino dice, not just dice that are already decomposing.

Manufacturer rejects, culls, souvenirs and fakes

There is a bunch of crap out there, and I hate to see people paying good money for casino dice that are not authentic. With the wonder of the web, I will show you in graphic detail how to spot dice that are fakes or souvenirs.

Manufacturers reject is a die or dice that cannot be used in actual play because they are not perfect in some way. A cull is (for the most part) the same thing as a reject but for different reasons. A cull is not used in play because they are imperfect, or there was an order overage (if a casino orders 500 pairs, the manufacturer doesn’t set out to make just 500 pairs, they take into account imperfections and may make many more than the amount ordered), or the colour or finish was not the type ordered (sometimes the manufacturer will make an issue in every colour and finish combination to show the casino what they would look like for possible future orders).

There are reasons for the fake and souvenir dice out there. It is different from the intentional manufacturing of closed casino “commemorative” chips that have come out in previous years. These kinds of chips were well-intentioned, but many collectors were duped by dealers passing the chips off as authentic.

Whenever a defect is discovered during manufacture, instead of throwing out the offending cube, it is stamped with a logo and thrown into the for sale bin. These are relatively easy to spot because they are often times not finished. That is to say that the process was not completed because of the defect. Sometimes the logo’s are raised up and you can feel them with your finger (Fig.1). On others you can see the lines from the scalping machines, meaning that the sides of the cube were not finished (Fig.2). This is hard to see without looking at the die itself, so I enhanced Figure 2 to accentuate the lines.

The primary clue to reject, cull, and “souvenir” dice is their perfect condition. You always have to be careful of dice from casinos that have been closed for years that look brand new. This is not to say that dice in perfect condition do not exist from very old casinos, but you will always see some wear and tear around the edges from table play, and maybe some logo wear. The exception to this is sticks. Many sticks, whether in foil or plastic cases, have not seen play. If you find a stick of dice from an old casino that are in perfect condition, you can be reasonably sure they are not culls or “souvenir” dice.

There are dice out there being sold as authentic that are NOT original to the casino. The seller can claim the dice are authentic because they own the original stamps from the various casinos, but the dice they are using the stamps on are manufactured daily. These dice (Fig. 6) are easy to tell from the real dice (Fig. 7). They are all stamped in bright gold colour and use a red die with a sand finish. The easiest way to spot these dice is that they will have no wear on the edges. Authentic casino dice that were used on the tables will have some dings or knicks along the edges from being thrown and bouncing down the table.

Figure 6 “Authentic Dice”
Figure 7 Real Silver Bird Dice