Ability score rolling method calculator

Computes probability distributions for ability score rolling methods.

Try the full-frame GitLab version with shareable URLs.

Features

• Runs locally in your own browser. While it can run on mobile, I recommend using a desktop or laptop.
• Change the number of dice, size of dice, how many dice to keep, modifiers, number of candidates per ability score, number of ability scores (taking the 6 highest), and number of candidate arrays.
• Computes probability distributions for each of the top 6 ranked ability scores for a single array, and 5e/Pathfinder point buy mean and standard deviation for the best of multiple arrays.
• Share rolling methods using the URL.
• Uses a direct computation---not Monte Carlo. The precision is only limited by floating-point operations.
• Runs with interactive performance once loaded.

How does it work?

I built this using Pyodide, Chart.js, and of course, my own hdroller Python library. A polynomial-time algorithm for keep-highest allows this calculator to deliver precise results at an interactive rate.

Compare previous AnyDice and Monte Carlo approaches.