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RPG Dice Probability

Calculate exact probability distribution for any dice notation (3d6+2). Bar chart, cumulative probability, advantage/disadvantage.

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e.g. 2d6, 1d20+5, 3d8

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RPG Dice Probability Calculator — Analyze Dice Rolls and Distributions

The RPG Dice Probability Calculator analyzes any dice notation (e.g., 2d6+3, 4d8-1, 1d20) and computes the full probability distribution, expected value, standard deviation, and minimum/maximum outcomes. Visualize results as histograms and cumulative probability charts.

Enter standard dice notation and the tool enumerates all possible outcomes, calculating the exact probability for each result. For complex expressions, it uses efficient convolution algorithms to combine multiple dice distributions. The histogram clearly shows the bell curve that emerges from rolling multiple dice, while the cumulative chart answers "what's the probability of rolling X or higher?"

Tabletop RPG players use this tool to evaluate weapon damage, compare character builds, and understand the odds behind critical game decisions. Game designers use it to balance combat mechanics and loot tables. Math students explore probability theory and discrete distributions through interactive dice simulations.

RPG Dice Probability Calculator is part of the facilita.tools suite of free browser-based utilities for gamers and designers. Available in Portuguese, English, and Spanish, optimized for desktop and mobile browsers.

Frequently Asked Questions

What dice notation formats are supported?
Standard RPG notation like 2d6, 3d8+2, 1d20-1, and 4d6. You can specify the number of dice, the die type, and optional modifiers with + or -.
How is the probability distribution calculated?
The tool enumerates all possible outcomes and calculates exact probabilities using convolution. For 2d6, it evaluates all 36 combinations to determine that 7 is the most probable result (16.67%).
Can I compare two different dice rolls?
Yes. Enter different dice expressions and compare their expected values, ranges, and probability distributions side by side using the generated charts.