A 10-sided die, often abbreviated as a “d10,” is a polyhedral gaming die with ten equally-sized faces, each marked with a different number from 0 to 9. In board and card gaming, it is used as a randomizer to generate a number between 0 and 9.

Here are some key points about the 10-sided die:

1. Number Range: A standard 10-sided die contains the numbers 0 through 9, inclusive. This makes it suitable for generating numbers with a range of ten possibilities.
2. Percentile Rolls: In some role-playing games (RPGs), two 10-sided dice are used in tandem to simulate a percentile roll. One die represents the tens digit, and the other represents the ones digit. This allows for the generation of numbers from 00 to 99.
3. Usage in RPGs: The 10-sided die is a common tool in role-playing games, where it’s used to determine various outcomes, such as the success of an action, the damage dealt, or other numeric variables.
4. Unique Number Distribution: Unlike a standard six-sided die, a 10-sided die has a more spread-out range of values, which can be useful for games requiring a greater diversity of outcomes.
5. Customized Variations: Some 10-sided dice are designed with non-standard numbering, such as those used in special RPG systems or unique board games.
6. Shape and Appearance: A 10-sided die is typically shaped like a pentagonal trapezohedron, which is a solid with ten faces, each of which is a trapezoid.
7. Fairness and Randomness: When properly manufactured and balanced, a 10-sided die should be equally likely to land on any of its ten sides, making it a reliable randomizer.
8. Versatility: While primarily used in RPGs, the 10-sided die can find application in various board and card games, especially those that involve elements of chance, numerical outcomes, or variable results.

The 10-sided die is a versatile tool used in a wide range of gaming contexts, providing a reliable means of generating random numbers within a specific range. Its role in RPGs is particularly prominent, where it helps to determine the outcome of various in-game events and actions.