Are Your Dice Balanced? (And Does It Even Matter)

Ever wondered if your handmade dice are really giving you a fair roll? Or perhaps you feel like the new dice you bought are cursed? You may not be wrong! While casinos demand absolute fairness in every roll (hopefully), TTRPG games usually don't mind a touch of unpredictability. 

Before you ask that poor dice maker on Instagram "ARE YOUR DICE BALANCED?" first ask yourself... does it even matter?

What Makes a Die Unbalanced?

It really comes down to precision and consistency in weight distribution. If a die lacks dimensional accuracy, meaning it’s not perfectly symmetrical, certain sides may be slightly heavier or lighter, which can affect how it rolls.

Even a small difference in shape can subtly shift the die’s centre of gravity, making some faces more likely to land face down than others. This is especially important for games where fairness and unpredictability are crucial (such as Casino Craps), as even a slight asymmetry can lead to noticeable biases in rolls over time.

Another common cause of imbalance is uneven density within the die itself.

Dense objects or air pockets embedded close to a particular face can disrupt the die’s weight distribution, tipping it towards or away from that face. For example, a tiny air pocket trapped near one side can make that side lighter, increasing its chances of landing on the opposite face. Similarly, adding heavy inclusions, like metal or stone, without careful placement can throw off the dice’s balance.

A perfectly balanced dice needs to have perfect dimensional accuracy on all axis as well as perfect solid density. Please note: Even an industrial CNC may have a tolerance of ± 0.005″ or 0.13 mm. This means that perfect dice are virtually impossible.

Even if you have a perfect dice in every regard, do you have a perfect surface to roll them on? Minute differences in the fibre or surface could affect outcomes. The way they're rolled is also a huge factor - perfect dice on a perfect surface rolled using an imperfect technique could affect outcomes.

You see the problem? 

How much does it matter?

Are you using them to win/lose money? YES. I want the fairest dice possible! For gaming? NO! C'mon people. It's a game!

When it comes to minor imperfections like a tiny bubble or an over-sanded edge, the difference in balance is often minimal—likely only a few microns. These minor flaws may technically shift the weight, but for most tabletop gaming, they won’t noticeably affect how the dice roll. In fact, it’s so small that in real-world gaming, the difference is almost undetectable. RPGs and casual games thrive on creativity and unpredictability, so minor variations don’t usually change the overall experience. While perfection might be crucial for high-stakes scenarios, in role-playing, a bubble or slightly uneven edge just adds character to the dice without compromising the fun.

My dice must be perfect

If you’re after mathematically perfect dice with flawless balance, handmade dice might not be the best choice.

Crafting dice by hand, while incredibly rewarding and unique, introduces small variations that are difficult to control. Even with the best techniques, there’s a level of precision that can’t quite match machine-made dice designed specifically for balance, like those used in casinos.

Handmade dice are often crafted with artistry in mind, adding inclusions, pigments, and even slight imperfections that give each die its own character.

For most tabletop gamers, this uniqueness enhances the experience, but for absolute mathematical precision, machine-produced dice are the way to go.

Think mass produced dice are perfectly balanced? Think again. There have been numerous tests conducted and significant complaints about mass produced dice on Reddit and other social media platforms. 

There was a fantastic experiment by Awesome Dice in 2019 comparing the randomness of Chessex and GameScience d20 dice, each die was rolled 10,000 times to assess fairness. 

The Chessex d20 exhibited a standard deviation of 78.04, indicating less uniformity in its roll outcomes. The GameScience d20 had a lower standard deviation of 60.89, suggesting more consistent results. However, the GameScience die showed a significant bias against rolling the number 14, likely due to a manufacturing artifact known as a sprue mark on the opposite face. This imperfection affected the die’s balance, leading to fewer occurrences of 14.

Source: https://www.awesomedice.com/blogs/news/d20-dice-randomness-test-chessex-vs-gamescience

Minimising balance issues

As a dice maker, it’s essential to aim for relatively fair rolls in your creations, especially if they’re intended for gameplay rather than purely decorative purposes.

While many makers enjoy the freedom of creating unique, artful pieces with intricate inclusions or unusual shapes, it’s a good idea to balance aesthetics with functionality for gaming dice.

Note: A fair die isn’t necessarily flawless, but it rolls in a way that doesn’t favor certain sides too heavily.

I mean, a dice that often rolls 20s could be cool, but ultimately it's going to diminish yours and your parties game play! 

Got a dice that often rolls low? Consider gifting it to your DM/GM!

On to the tips!

1. Use a Pressure Pot - A pressure pot compresses air bubbles down to tiny, nearly invisible specs, so they won’t affect the dice’s balance or appearance. This can be a game-changer for achieving a smooth, balanced finish. Those surface bubbles you're always fighting against may create minute weight imbalances that could affect their fairness.
   
   
2. Ensure All Inclusions Are Made of Resin - Different materials have varying weights, which can create imbalance if not considered.
   
   For example: Using 3D-printed resin or cast resin inclusions keeps everything uniformly dense and balanced. As long as the dice and the inclusions are made of the same stuff, they effectively create a single solid mass that's devoid of any possible imbalance.
   
   
3. Avoid Using Heavy Inclusions - inclusions like stone or glass, as these can shift weight to one side. Again, if the dice are "artistic" pieces, add whatever you want (but don't expect them to be welcome at Adventure League :P)
   
   If you must mix materials, keep heavier items small and spaced evenly. Easy in concept, but almost impossible to do without multiple castings.
   
   
4. Carefully Distribute Inclusions - Spread glitter, small flowers, or other light inclusions evenly. If they clump or gather in one area, they could skew your dice’s balance.
   
   
5. Choose High-Quality Moulds - High-quality moulds help ensure uniform shapes and edges, which can improve the dice’s weight distribution and roll accuracy. Again, these are gaming dice, both 3D printing and resin have inherent shrinkage that affect them causing issues with dimensional accuracy.

Testing the Balance of Your Dice

Once you’ve crafted your dice, try these methods to test for balance:

• Saltwater Float Test
  Create a dense saltwater solution that will float your dice. Give the die a gentle spin in the solution and see if a particular face consistently rises. If it does, your dice might have a balance issue.
  
  Check out https://thecriticaldice.com/blogs/news/how-to-salt-water-test-your-dice
  
  
• Roll Test
  Roll your die 100 times or more, tracking each result. Ideally, each number should appear at roughly the same frequency. If one or two numbers appear far more often, the dice may be unbalanced. Note: this is extremely oversimplified and identifying any statistically significant bias may take thousands of roles.

When to Prioritise Balance in Dice Making

• For Casual RPGs:
  For most RPG settings, slight imbalances are part of the charm. If you’re creating dice for casual play or personal use, a little unpredictability isn’t usually a problem! 
  
  
• For Competitive Play:
  If you’re making dice for a competitive game or aiming for a balanced roll, investing the extra time to create balanced dice is worth it. Following the tips above can help you create a more reliably fair set.

Wrapping It Up

Crafting your own balanced resin dice is both an art and a science. While absolute balance is essential for high-stakes games, in RPGs, it’s all about fun, so small imbalances may go unnoticed. With a little practice, and by keeping materials and inclusions consistent, you can create dice that roll fairly and look incredible.