About Dice Together

Dice Together started from a simple annoyance: at the moment you need a die, there's never one around. So I made one that's always within reach, in your browser on any device.

What this is

The main thing on Dice Together is the online dice roller: open the page and you're rolling right away, up to twelve dice at once. The dice tumble across the screen in 3D, with the sound of a rolling die. Every roll lands at random, just like the real thing, so you can use it for any board game.

That comes in handy at exactly those moments when you don't have a physical die within reach:

• Board games and party games where a die has gone missing or rolled under the couch.
• In the classroom, to demonstrate probability or as a fair way to pick someone. There is a classroom dice roller set up for that.
• On the go, on your phone, without having to install anything.
• To demonstrate odds, for example how often you roll a six on average.

Besides the dice roller, the site has write-ups of the best dice games, from Yahtzee to bluffing games. Each one covers the rules, the scoring, and a few tips, so you can join in right away.

How it works

It's deliberately simple. The dice are rendered in 3D with WebGL, the standard technology for 3D graphics in the browser, so everything runs on your phone, tablet, or computer without installing anything. All you need is a modern browser.

Every roll is random, and every face has the same chance. The next section explains how that's done. For the size of those chances, read the guide to dice probability, with the odds per roll and per combination.

How the randomness works

It's worth being precise about this, because "random" is an easy thing to claim. Every roll starts by choosing the resting face, before anything moves: one call to Math.random(), scaled to the number of faces on that die and rounded down, picks a single face out of that die's list. That's the standard uniform pick: the face is chosen directly rather than added up from several numbers, and no result is discarded and re-drawn, so on a d6 all six faces have the same chance, and the same goes for the d4, the d20, and the percentile die.

The tumble you watch is added afterwards. The animation spins the die through a whole number of extra turns on its way to the face that was already picked, which is why it always settles flat instead of balancing on an edge. How long it tumbles, how many turns it makes, and how hard you tapped make no difference to the outcome, because the outcome existed before the animation began.

There is one limitation. Math.random() is the pseudo-random generator built into your browser. It's the right tool for a board game, a classroom demo, or settling who goes first, and that is what this was built for. It is not cryptographically secure, and I make no claim that it has been audited or certified. Don't use it for gambling, for anything security-related, or to draw a prize winner. Those need a source designed for that job.

The free Android app

For board game nights there's a bonus: the free Android app. It lets you roll the dice on your phone and see them appear big on your TV right away, streamed via Chromecast or on an Android TV. That way everyone at the table watches the same roll.

Otherwise the app works just like the website: the same 3D dice, the same sound, no ads, and no account. It's free on Google Play. The Android app page has the install link, the list of TVs it works with, and the answer for iPhone owners.

Who's behind Dice Together

Dice Together is built and run by one independent developer. There is no studio behind it and it isn't part of a network of content sites. I write the code, ship the Android app, and read the mail that comes in. That's also why the site stays small: a dice roller that opens instantly, and game rules you can play from.

The website and the app are both free. There are no ads on either, nothing is for sale, and there's no account to create, so there's nothing to cancel later. What little the site measures is anonymous and aggregated, and the next section says what that is.

The site comes in two languages, each on its own address: English here, and Dutch at dobbelsteen.app.

Privacy & contact

I care about privacy, so this stays simple. You don't need an account, and the dice roller doesn't ask for personal data to do its job. How the site is used is measured anonymously and in aggregate, and nothing more, so the pages can keep getting better. What is and isn't collected is in the privacy policy.

Spotted a rule that doesn't match how your table plays it, or a game that's missing here? Write to dice@itl.dev and say so. Corrections are the most useful mail this site gets, and requests for games to cover next are a close second.