🎲 Dice Roller

Type a roll in NdM+K notation or click one of the classic presets and the dice are resolved instantly, with the total and the individual die faces shown side by side. It is a tabletop dice roller that stays honest about how the number was reached.

Notation and Limits

The accepted pattern is a count, the separator d, and a number of sides, with an optional signed modifier at the end: 2d6+3, 4d8-2, 1d20. Whitespace is allowed around every part and the separator is case-insensitive. The count must be between 1 and 100, and the sides must be between 2 and 1000. The modifier is optional and may be positive or negative; when it is omitted it counts as zero. A notation that does not match this grammar, such as a bare d20, a missing side count, or a term like 2d6+1d4, is rejected with a clear inline error rather than a best-effort guess.

Worked Example: Rolling 2d6+3

Enter 2d6+3. The tool rolls two six-sided dice separately and adds three to their sum. A particular run might produce faces of 4 and 6, giving 4 + 6 + 3 = 13. The result panel shows the total, 13, and lists the two faces plus the modifier so you can audit the arithmetic. Rerolling the same notation draws fresh faces; the modifier never changes unless you edit the notation. For a damage roll in a tabletop game, this is exactly the number to announce, and the visible breakdown means a disputed roll can be verified after the fact.

The Distribution Behind the Total

A single dN is uniform: each face from 1 to N is equally likely, and the expected value is (N + 1) / 2. Multiple dice are not uniform because there are more ways to reach middle values. For 2d6 the 36 ordered outcomes produce this shape:

Total	2	3	4	5	6	7	8	9	10	11	12
Ways	1	2	3	4	5	6	5	4	3	2	1

Seven is the peak, with six ways out of 36. That is why 2d6 feels more predictable than 1d12 even though both can reach 12; 1d12 is flat at one way per face, while 2d6 clusters around the middle. Adding a constant modifier shifts the whole curve without changing its shape, so 2d6+3 peaks at 10.

Presets and History

The seven preset buttons roll a single d4, d6, d8, d10, d12, d20, or d100 with one click, which saves typing during fast play. Every roll is appended to a session history that keeps the most recent 20 results with their notation and total. History lives in memory only: it is never persisted, never uploaded, and clears when you reload or close the page. A clear button empties it on demand.

Common Mistakes

• Forgetting the leading count. The grammar expects 1d20, not d20. A bare d20 is an invalid notation.
• Assuming advantage is built in. It is not. To emulate advantage, roll 1d20 twice and take the higher face yourself.
• Mixing die types in one expression. Expressions like 2d6+1d4 are not supported; roll each group separately and add the totals.
• Reading 2d6 as flat. New players often expect every total from 2 to 12 to be equally likely. The table above shows otherwise.
• Expecting the modifier to multiply. A modifier is always added or subtracted, never applied to each die, so 2d6+3 adds 3 once, not 3 per die.
• Looking for the history after a refresh. Because it is session-only, the list is gone after a reload; capture anything you need before then.

Practical Tips

A few conventions make the roller easier to use at the table. Announce your notation before rolling so everyone can see what was requested; the history entry keeps both the notation and the total, which settles disputes without a re-roll. For damage, roll the dice group and add the modifier in the same expression rather than doing the addition in your head, so the breakdown stays visible. When a rule calls for rolling on a table with more than 20 entries, use the d100 preset and map the result to your table rather than rolling several dice. For a percentile check, a single d100 is flat, while 2d10 added together gives the familiar curved distribution; pick the one the system intends. If you need several independent groups in one turn, roll them one after another and read each history line, since the tool records each call separately. And keep in mind that the total is the sum plus the modifier, so a negative modifier can push a total below the dice minimum: four ones on 4d6-2 total 2, not 4.

The crypto-backed random source means you cannot influence the outcome by timing a click, and rerolling does not trend toward any value. That fairness is the point, but it also means streaks happen: three low rolls in a row are normal, not a sign of a broken tool. If you are teaching probability, roll the same notation many times and tally the totals; with enough rolls the 2d6 curve from the table above becomes visible, and the flatness of 1d12 stands in clear contrast. Because results are kept for the session only, note or copy anything you want to keep before reloading the page.

Related Tools

• Random Number Generator
• Random Decision Maker
• Team Generator