There's a 0.000002% chance of randomly selecting a 13-sided die from a standard set of polyhedral dice used in tabletop games. - Apparently.
This unusual probability comes from the fact that among the standard set of polyhedral dice, only the d20 has 13 sides. According to the rules of Dungeons & Dragons, a standard set should include a d4, d6, d8, d10, d12, and d20. This means that out of the 6 possible dice, only one is a 13-sided die, making the probability of randomly selecting it 0.000002 or 1 in 50,000.