Percentile Dice Roller (d100)

What this generator does

Rolls percentile dice — a single number from 1 to 100, the same spread as a tens die and a units die read together. It is the standard mechanic in percentile-based tabletop systems, where difficulty is expressed as a percentage chance.

How to use this tool

1. Choose how many d100 to roll.
2. Roll to see each result and the total.

Worked examples

A roll-under skill check

A character with a 62% skill succeeds on any roll of 62 or below. Rolling one d100 and reading it against the skill value is the entire check — no modifiers to add first.

Common use cases

• Percentage-based random tables
• Tabletop RPG percentile checks
• Any game needing a 1-100 random number

How this generator works

Rather than simulating a physical tens die and units die as two separate objects, each roll draws a single whole number from 1 to 100 directly from your browser's Web Crypto generator, with the range conversion corrected so every value is exactly as likely as every other — mathematically identical to reading a tens die and a units die together, without needing two dice on screen.

Randomness and fairness

Each d100 is a single draw from 1 to 100 made with your browser's cryptographic random number generator, so all one hundred results are equally likely. A seed swaps in a deterministic, non-cryptographic generator, which reproduces the same rolls from the same word. Reach for it when a table needs to replay a roll, never when the roll is meant to be unpredictable.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

• Every value from 1 to 100 is equally likely, so a roll-under target of 35 succeeds 35% of the time. There is no bell curve here, unlike rolling multiple dice and adding them.
• Rolling several d100s at once totals them, which most percentile systems never do — a percentile check reads one roll against a target, so use a count of 1 unless your table's own rule calls for summing several.