Know the odds
Probability, made playable.
Expected total7
Chance2.8%
Rolls this session0
D100 roller
Roll a d100, online and free.
A dedicated percentile dice roller — one flat, uniform result from 1 to 100 for random tables, wild magic, loot drops, and roll-under skill checks. Instant, fair, and no pair of d10s to add up. No app, no sign-up.
🔥 0-day streak
ROLL CONFIGURATION1d100
Share a room and everyone sees the same rolls live — no more "did you actually roll that?"
Room
total—
Try 1d100, 1d100+10, or 2d100 for two tables at once.
Why a dedicated d100 roller
The d100 — percentile dice — is the die of random tables. Game masters lean on it for treasure and loot drops, wild magic surges, trinket and rumour tables, critical charts, and encounter rolls, while entire systems (Call of Cthulhu, RuneQuest, Warhammer Fantasy Roleplay) resolve every skill check as a roll-under on a d100. This page gives one flat 1–100 result per click, with a live history so a table-heavy session doesn’t lose its place, and modifier presets for the +10 / −10 adjustments many tables call for.
Every value from 1 to 100 has an equal 1% chance, drawn locally in your browser with no seeding — the same distribution as a well-made pair of d10s, without the mental arithmetic. To roll the tens-and-ones pair by hand instead, use the d10 roller. For the full polyhedral set use the D&D dice roller, or the main roller for custom notation.
Frequently asked questions
How do I roll a d100 online?
Use the roller above — it defaults to a single d100 and gives a flat, uniform result from 1 to 100. Click "Roll dice", press space, or use a preset. Add a modifier with notation like 1d100+10.
Is a d100 the same as percentile dice?
Yes. Percentile dice are traditionally two d10s — one for the tens digit, one for the ones — giving a result from 1 to 100 (00 + 0 reads as 100). This roller does the same thing in a single roll. To roll the pair yourself, use the d10 roller.
What are the odds on a d100?
Every result from 1 to 100 has an equal 1% chance, with an average of 50.5. There is no bell curve — a d100 is as flat as a d20, just with finer granularity.
What is a d100 used for?
Random tables of all kinds: loot and treasure drops, wild magic surges in D&D, trinket and NPC-quirk tables, critical-hit charts, and encounter generators. Whole systems — Call of Cthulhu, RuneQuest, Warhammer Fantasy Roleplay — resolve skill checks on a d100 roll-under.
How does a roll-under d100 check work?
In percentile systems your skill is a number from 1 to 100. You succeed if the d100 rolls equal to or under that number, so a skill of 65 succeeds 65% of the time. Lower rolls are often better (and may be a critical success); high rolls fail.