Beautiful 3D dice extension for d20 based systems, forked from Owlbear Rodeo Dice.
Dicex extends the upstream Owlbear Rodeo dice roller with the following:
- Exploding dice — Dice that hit their max (or a specified threshold) automatically reroll and add to the total. Supports
!,!>N, and exact-value explosions. - Keep/drop — Roll extra dice and keep the highest or drop the lowest (e.g.
4d6k3for classic stat rolling). - Advantage/disadvantage — Toggle to automatically double your dice pool and take the highest or lowest result. Handles paired d100+d10 correctly.
A full notation parser and serializer supporting expressions like 4d6!k3+2. Used throughout presets, chat messages, and the audit log.
Save, load, and edit named roll configurations. Presets persist per-player in OBR room metadata and can be quickly loaded from a picker menu. The active preset name is shown in chat messages.
Roll results are automatically posted to Owlbear Rodeo's Rumble chat with smart formatting — individual die values grouped by type, emoji markers for crits (⭐), fumbles (💀), explosions (💥), and dropped dice (🚫). Hidden rolls are only visible to the rolling player and the GM.
Every roll is recorded with timestamp, notation, individual die results, total, and advantage mode. The GM can export the full table's roll history as JSON or clear the log.
Hidden Rolls
A visibility toggle that defaults to hidden for GMs and visible for players. Hidden rolls are excluded from the public Rumble chat feed and only sent to the roller and GM.
Other Owlbear Rodeo extensions can ask dicex to roll on their behalf, using the Dice+ broadcast protocol. A request is sent on dice-plus/roll-request with { destination: "LOCAL" }; the result comes back on {source}/roll-result, or an error on {source}/roll-error. The authoritative payload types are exported from src/plugin/dicePlusProtocol.ts.
Roll visibility is source-gated. A request carries a rollTarget, but "everyone" produces a visible roll only when the requesting extension's source id is listed in TRUSTED_ROLL_TARGET_SOURCES. Every other combination is hidden:
rollTarget |
Trusted source | Any other source |
|---|---|---|
everyone |
visible | hidden |
self / dm / gm_only |
hidden | hidden |
This is an allowlist because the failure modes aren't symmetric — a roll wrongly made public can't be taken back, while one wrongly hidden is a minor annoyance. An unrecognized source is therefore always hidden.
Two consequences worth knowing before integrating:
everyonefails silently if you aren't listed. The roll succeeds and reports back normally; it's just hidden. There's no error. If your integration's rolls are unexpectedly private, this is why — open an issue to have your extension's id added.- Dice+ rolls never alter the user's tray toggle. Visibility is passed per-roll, so a request cannot leave the user's own hidden setting changed.
Add the extension to Owlbear Rodeo using this manifest URL:
https://abottchen.github.io/dicex/manifest.json
This project uses React for UI, Three.js for rendering and Rapier for physics.
The physics simulation is used to both generate the animation for the roll as well as the final roll values.
Wait is it really random if physics is used to determine the result? How do I know the dice rolls are fair?
Short answer yes, the dice are fair. Long answer here's a statistical analysis of the rolling methodology.
In order to sync rolls over the network efficiently we rely on the fact the Rapier is a deterministic physics engine. This means that across two different computers we'll get the same result given the same initial parameters.
So we only need to make sure that all the initial parameters are synced and then each client can run its own simulation and end up with the correct animation.
To try out the dice roller outside of Owlbear Rodeo you can head to https://dice.owlbear.rodeo/.
This project uses Yarn as a package manager.
To install all the dependencies run:
yarn
To run in a development mode run:
yarn dev
To make a production build run:
yarn build
All source files can be found in the src folder.
If you'd like to create a new dice set with the existing dice styles edit the diceSets.ts file in the sets folder.
If you'd like to add a new dice style the 3D models for the dice are split across four folders: materials, meshes, colliders and previews.
The materials folder contains the PBR materials for each dice style.
The meshes folder contains the 3D geometry used for the dice.
The colliders folder contains the simplified collider geometry for the dice.
The previews folder contains 2D image previews for each dice.
All the code specific for the Owlbear Rodeo extension is in the plugin folder.
GNU GPLv3
This project is provided as an example of how to use the Owlbear Rodeo SDK. As such it is unlikely that we will accept pull requests for new features.
Instead we encourage you to fork this repository and build the dice roller of your dreams.
Copyright (C) 2023 Owlbear Rodeo