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Full-Text Articles in Mechanical Engineering

Dice Are Blessed Or Cursed, Warren Campbell, Cameron Miller Jan 2024

Dice Are Blessed Or Cursed, Warren Campbell, Cameron Miller

SEAS Faculty Publications

Dice are cursed or blessed; that is, they roll low or high, but they are never fair. They cannot be manufactured with uniform density and geometric precision. This is particularly true of 20-sided dice or D20s. Faces are smaller than 6-sided dice, and manufacturing tolerances are similar. However, some dice are fairer than others. In our studies of plastic-mold dice about 1 in 4 test fair in 3000 rolls. We have used different statistical tests, including chi-square, modified Kolmogorov Smirnov, and double binomial tests. Of these, the method that consistently performed better is the chi-square goodness of fit test. The …


Dice Testing With The Running Chi-Square Distribution, Warren Campbell, Hunter Wimsatt Jul 2022

Dice Testing With The Running Chi-Square Distribution, Warren Campbell, Hunter Wimsatt

SEAS Faculty Publications

Dice are not fair. Producing a geometrically precise, uniform die is not possible. Casino dice come as close as possible to perfectly random dice because they are machined to an accuracy of a few ten-thousandths of an inch and the putty used for the pips (dots) is the same density as the plastic die body. Polyhedral dice used in games like Dungeons and Dragons are far more difficult to manufacture to high tolerances. Some dice are fairer than others. Since 20-sided dice (D20s) are very difficult to manufacture precisely, they were the focus of this study. The running chi-square distribution …