At their buy dice bulk, dice are supposed to be random number generators. A six-sided die (D6) should, in theory, have a 1 in 6 chance (or about 16.67%) of landing on any one of its faces. This principle of fairness extends to other dice shapes, such as 10-sided (D10), 12-sided (D12), and 20-sided (D20) dice. However, real-world dice are not always perfectly random due to a variety of factors.

In an ideal world, rolling a fair six-sided die 600 times should give you roughly 100 results for each number. However, in practice, this balance is rarely perfect. Why does this happen? Here are some reasons:

Manufacturing Imperfections and Uneven Weight Distribution

One of the main reasons some dice might roll higher numbers more often is manufacturing inconsistency. Mass-produced dice, especially when bought in bulk, often have tiny flaws that can affect their balance. These flaws may include:

  1. Uneven Weight Distribution:

    • The material used in the dice, such as plastic or resin, may not be evenly distributed. If one side of the die is slightly heavier than another, it will influence how the die lands.
    • Air bubbles trapped inside dice during the molding process can make certain sides lighter, increasing the probability of rolling certain numbers.

  2. Imperfect Shapes:

    • Even though dice appear symmetrical, imperfections in the casting process can cause slight deviations. If an edge is slightly sharper or a side is not entirely flat, the die may favor rolling on certain faces more than others.

  3. Misaligned Number Engraving or Printing:

    • The process of engraving or painting numbers on dice can cause weight imbalances. Deeper engravings on one side of the die may remove more material, making the opposite side slightly heavier, which influences rolling tendencies.

Plastic vs. Metal Dice: Does Material Matter?

Another factor that affects rolling probability is the material from which the dice are made. Bulk dice are commonly made from plastic or resin, but some people prefer metal dice, which have a significantly different weight distribution.

  • Plastic Dice: These are lightweight and may have more imperfections due to air bubbles or slight molding inconsistencies. Because of this, plastic dice might be more prone to rolling higher numbers if they have minor weight imbalances.
  • Metal Dice: These are much heavier and tend to have more precise manufacturing processes. While metal dice are less likely to suffer from weight imbalances, their increased weight means they tend to roll less and "settle" faster, reducing randomness.

If you’re buying dice in bulk, the likelihood of encountering unbalanced plastic dice is much higher compared to precision-machined metal dice.

Injection Molding and Mass Production Errors

Most bulk dice are manufactured using an injection molding process, which involves injecting molten plastic into a die-shaped mold. This process, while efficient, introduces small errors that can cause imbalance.

Some common errors in mass production include:

  1. Shrinkage During Cooling:

    • When the plastic cools, it contracts slightly. If one side contracts more than another, it can create a minor weight imbalance.

  2. Ejection Pin Marks:

    • During manufacturing, dice are removed from molds using ejection pins. If a pin presses harder on one side, it might slightly warp the die’s shape.

  3. Layering of Plastic:

    • Some dice have layered plastic for color effects. If the denser material is at the bottom, it could make the dice favor certain faces.

These minor inconsistencies, when combined across thousands of dice in bulk purchases, can lead to noticeable rolling patterns.

Are Some Dice "Lucky"? The Role of Psychological Bias

Even when two dice have identical shapes and weights, many people believe certain dice roll higher numbers more often. This perception is often a result of psychological bias rather than actual dice mechanics.

  1. Selective Memory:

    • Players tend to remember rolls that confirm their expectations. If a die rolls high numbers a few times in a row, a person is more likely to believe it is "lucky."
    • However, they often forget the times it rolls low numbers, leading to a skewed perception of randomness.

  2. Confirmation Bias:

    • If someone believes a specific die rolls high more often, they may unconsciously roll it in a way that favors higher numbers.

  3. Rolling Techniques:

    • The way a person rolls a die can unintentionally influence results. A "soft" roll might favor numbers on one side more than a "hard" roll.