Roll20 rolls dice through a simple chat command: type /roll followed by a formula like 2d6+3, press Enter, and Roll20 prints each die face and the total in the Text Chat window along with a small die icon you can drag onto the tabletop. Roll20 is one of the most popular virtual tabletops for online tabletop RPGs like Dungeons & Dragons and Pathfinder, and its dice system is intentionally command-driven rather than graphical, so a new player typing into the chat box for the first time will not find a clickable dice tray. That design is powerful because it supports formulas, modifiers, advantage, secret rolls, and full macros, but it also explains why so many searches land on a phrase like "how to roll dice in Roll20." This article walks through the standard Roll20 chat workflow, then shows a simpler browser-based alternative for the times when you just need a fair roll without opening a campaign.
The /roll Command in the Roll20 Chat Box
The standard Roll20 workflow lives in the Text Chat tab at the bottom of the Roll20 tabletop. Open the chat, type /roll, then a dice formula, then press Enter. Roll20 parses the formula, rolls each die on its server, and prints the result inline in the chat with a small graphical icon next to it that you can drag onto the map as a token.
The basic formula format is [count]d[sides][+/-modifier], where count is how many dice to roll, sides is the number of faces, and modifier is an optional number added or subtracted from the total. A few quick examples cover most of what you need in a typical D&D session:
- /roll 1d20 rolls one twenty-sided die and is the default for attack rolls, saving throws, and ability checks.
- /roll 2d6+3 rolls two six-sided dice and adds 3, which is a common damage roll for shortswords, daggers, and many monster attacks.
- /roll 4d6kh3 rolls four six-sided dice and keeps the highest three, which is the classic D&D ability-score roll.
- /roll 2d20kh1 rolls two d20s and keeps the highest, granting advantage; swap to kl1 for disadvantage.
Roll20 also accepts short aliases. /r is the same as /roll, and /roll d% or /roll 1d100 produces a number from 1 to 100 for percentile tables, loot drops, and random encounters. For private rolls, use /gmroll to send the result only to the game master, or /w <player-name> to whisper a roll to a specific player.
Standard Roll20 Dice and What Each One Is For
The seven standard polyhedral dice that show up in tabletop role-playing games are all available in Roll20 out of the box. The table below summarizes the most common dice, how to type them in chat, and what they are typically used for at the table.
| Die | Chat formula | Typical use |
|---|---|---|
| d4 | /roll 1d4 | Small weapon damage, healing potions |
| d6 | /roll 1d6 or 2d6 | Sneak attack, cantrip damage, many board games |
| d8 | /roll 1d8 | Longsword damage, rogue sneak attack dice |
| d10 | /roll 1d10 | Fireball damage, heavy crossbow |
| d12 | /roll 1d12 | Greataxe, barbarian rage damage |
| d20 | /roll 1d20 | Attack rolls, saving throws, ability checks |
| d100 | /roll 1d100 | Percentile rolls, random encounters, loot tables |
If a campaign needs an unusual die like a d3 or a d24, Roll20 still works fine: just type the formula with the number of sides you want, and Roll20 will roll that exact range.
When a Browser Dice Roller Is the Better Choice
Roll20 is excellent when you have a live campaign running and players are spread across multiple locations. There are plenty of situations, however, where launching Roll20 just to roll a die is more friction than the roll deserves. A few common cases include playing a board game in person when the physical dice have rolled under the couch, running a quick one-shot that does not justify setting up a campaign, finishing combat while a player reconnects, or teaching probability in a classroom where students want to see results instantly without accounts.
In those scenarios, opening a new browser tab and using a free Dice Roller tends to be quicker than signing into Roll20, picking the right campaign, and typing a command. The Dice Roller needs no login, no setup, and no character sheet — you choose a die, choose how many, and press Roll. It also works well alongside Roll20 rather than against it; some game masters keep a browser dice roller open for ad-hoc rolls, NPC-only checks, or quick rulings between turns.
Rolling Dice with the Dice Roller
The Dice Roller is a free online dice roller that runs entirely in your browser and never sends anything to a server. The steps below cover a single roll from start to finish.
- Pick a dice type — d4, d6, d8, d10, d12, d20, or tap Custom to enter any number of sides from 2 up to 1000.
- Set how many dice to roll using the − and + stepper, then press the Roll button. The tool accepts up to 12 dice of the same type in a single batch.
- Read each individual result, the total, your recent roll history, and session stats. The history stays visible on screen so you can verify a streak or check a previous roll without re-rolling.
If you need a die Roll20 does not expose by default — a d3, a d7, or anything exotic — open the Custom field and type in the sides you want. The roller then maps each result onto the range 1 to that number and applies the same fair random process used for the standard polyhedral dice.
Why Summed Dice Form a Bell Curve
One subtle property of dice shows up the moment you roll more than one at a time: the totals are no longer uniform. A single die is flat — every face is equally likely — but when you sum dice, the totals cluster around the middle and thin out at the extremes. With 2d6, the most common total is 7, because there are six different combinations that add to 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1) but only one combination each that produces 2 or 12. This bell-shaped distribution is the same pattern that shows up in insurance losses, measurement error, and quality control, which is why teachers use dice to introduce expected value and the central limit theorem.
The Dice Roller's built-in history and session stats make this visible in real time. Roll 2d6 twenty times in a row and the totals cluster around 7 with the occasional 2 or 12; the average-total stat slowly drifts toward the expected mean of 7. Roll20 can show the same shape through repeated chat rolls, but a browser tool with a permanent on-screen history is a more convenient way to demonstrate it.
Roll20 vs. a Browser Dice Roller
Both tools produce fair dice, but they are designed for very different jobs. The table below compares them across the dimensions that matter most when deciding which one to reach for.
| Feature | Roll20 | Browser Dice Roller |
|---|---|---|
| Setup needed | Account, campaign, table | None — open the page |
| Dice types | All standard plus custom sides | All standard plus custom (2–1000 sides) |
| Roll speed | Type a command in chat | Tap Roll |
| Roll history | Scroll up through chat | Visible on screen |
| Secret rolls | Built-in (/gmroll) | Not private by design |
| Maps, tokens, sheets | Full VTT | Dice only |
| Cost | Free tier + paid plans | Free |
| Works offline | No | Yes, once loaded |
The honest summary is that Roll20 is the right tool when you want maps, tokens, character sheets, and shared rolls with a remote group, while a browser dice roller is the right tool when you want the dice and nothing else.
Other Things You Can Do With Virtual Dice
Virtual dice rollers are useful well beyond D&D. They cover board games that lost their dice, quick tabletop combat at a kitchen table, fair random decisions such as who goes first or which movie to watch, and simple random-number generation within a fixed range — pick the Custom sides option and the die becomes a number picker. They are also a popular classroom aid because each roll generates real data: roll enough times and the running average settles near the true mean, which is a memorable way to learn probability. The Dice Roller keeps those rolls on your screen rather than sending them to a server, so classroom results, campaign outcomes, and personal decisions stay private.