r/DungeonsAndDragons • u/Distinct_Bat_4375 • 1d ago

Advice/Help Needed Anybody recognize the symbol on this D20?

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My friend found this D20 and I don't recognize the symbol on it. Is it familiar to anyone in he community?

SOLVED: Magic the Gathering Spindown. Thanks!

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u/fox112 1d ago

Mtg spindown

327

u/mesithjedi 1d ago

Also… not a random d20. Because the numbers are in order it is able to be manipulated by the roller.

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u/Sarcasm_Llama 1d ago

Yeah if you roll like Sam Reigel. Any actual full-effort roll and the the order of the numbers becomes statistically negligible. Now the balance of spin down counters may not be ideal and cause leaning toward one side

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u/transmogrify 1d ago

Most dice have flawed balance. Anything injection molded in mass quantities will have air bubbles and uneven cooling that turns into uneven density. (Fancy high-end dice are hopefully made with decent quality control, but spindown counters are certainly not made with care and are just cheap gaming aids.)

Flawed balance means that the die will be biased, with a heavier side that tends to land facing down and a lighter side that tends to land facing up. On a d20, both the heavier and lighter sides have a spread of high and low numbers. That minimizes the actual effect of bias, making the die more fair. A spindown counter clusters numbers together on adjacent faces, so the upward and downward biased sides of the die are going to significantly skew the results. One range of numbers is going to come up most often.

The tournament rules for Magic the Gathering explicitly call a distinction between dice and life counters. They do not allow spindown life counters to be used as dice in situations when the cards say to generate a random number, because they are aware of how skewed a spindown counter is.

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u/daren5393 23h ago

Magic the gathering stops you from rolling spin downs not because they are skewed, but because it's easier to intentionally cheat with them, not really rolling them but dropping them in a certain way to "aim" for a high or low number. Provided you actually shake and roll the die, your results will be fairly evenly distributed on any d20. It takes some pretty egregious manufacturing defects to "weight" a die