The lobby and invites
The lobby is where a campaign waits between sessions and before the first one: the cover, the room code, the party list, game settings, lore and rules, and the start button. Every member can open it; the lead and the Dungeon Master can act in it.
The room code
Every campaign has a room code of four to twelve letters and digits, drawn from an alphabet with no 0, O, 1 or I. It never expires on its own. The Room code panel in the lobby, and the invite dialog on the Party tab during play, show it three ways:
- The code, to read out loud. On an app-hosted world that is being shared, the code shows as two halves,
ABCD2345-EFGH6789: the host's code, which is also the tunnel's name, and the table's. A friend types the pair into their app and it finds your device with nothing else to look up. On a server with its own address the table's code stands alone, and the friend adds the server by address first. - The link,
https://opendungeonmaster.com/j?s=...&c=CODE. It opens an interstitial that names the destination and asks the person to confirm, then opens the app if it is installed, or the host's pages in the browser. - The QR code, of the same link. A phone camera opens the interstitial; the Android app's scanner joins directly.
Copy code, Copy link, and on Android and in a browser that offers it, the OS Share sheet. New code rotates the code and kills every old link and QR at once.
Sharing an app-hosted world
On a world hosted from the desktop or Android app, opening the lobby asks the app to share online. The invite reads "Opening a public address..." and then "Shared online" as the tunnel comes up, and every link and QR follows the public address. Stop sharing is in the same place and in the app's Settings; stopping keeps your host code claimed so only you can bring it back. If another device holds your host code, the lobby card and the invite dialog say so and offer a new code.
For a table in the same room, the desktop app's Settings also has Share on this Wi-Fi: the world answers on your local network with no internet, at a plain http address the app shows with its QR code. On a self-hosted server on a LAN, the server's own QR button (bottom right of every page) encodes its address for a friend on the same network.
Who can join, and when
- The code admits people while the campaign exists, has not ended, has a free seat, and is not mid-game with the door shut. Mid-game join in the settings opens the door after play starts.
- On an app-hosted world a guest joins with a name and nothing else. On a self-hosted server with invite-only sign-ups, a live room code lets a newcomer register without an account invite.
- Guesses are throttled like wrong passwords, so a leaked code cannot be brute-forced against.
- Invite links show a preview of the table before sign-in, so a friend can see what they are joining.
Seats and readiness
Each member picks a character from their library or builds one in place; the party list shows who is ready. The lead can remove a member, which frees the seat. Playing more than one character per player is a campaign setting.
The Dungeon Master seat
From the party list the lead can make DM (seat a person as the human Dungeon Master, which moves story authority to them), make co-DM (an assistant who shares the console) and remove co-DM. The DM runs no character and holds no party slot. A co-DM cannot hand the game to the AI; that takes the DM or the owner. A DM can open the table without owning the campaign. See Human DM mode.
Settings, lore and rules in the lobby
The lobby carries the campaign's game settings, its lore (party-visible entries), its house rules, and the import of workshop prep, all editable by whoever holds story authority. A world pack's places and factions show as a strip under the cover.
Starting
When the party is ready, the lead presses start. The Dungeon Master opens the first scene, and every player is taken to the table. Later sessions open straight from Continue on the title screen into the table; the lobby stays reachable from All campaigns.