Whoever is running this server gave you a secret out of band (a chat message, not a public page). It is kept in this browser only, never shown back, and sent with every lobby request.
You become the host — you choose the mode and, once everyone's seated, start the game. 2 to 4 players.
The same dials the solitaire New Game dialog has. Picking a mode or a table size sets them to that game's defaults; every one stays yours to change. They are fixed when the game is created and cannot be changed once it starts.
The same seed and the same settings always deal the same railroad, so a game can be shared, compared or replayed. Leave it blank for a random one.
What each player is dealt before the first turn. The hand limit is three either way — deal six and the first turn is spent choosing which of them to keep.
What each piece of work pays, 0 to 5. Zero switches an economy off so the others can be read.
How long the game runs, and the ways it can end. 0 turns any of these off. The combined-Revenue default is sized for the table you chose above.
Not yet built (TODO.md) — this has no effect
either way until then.
Appendix B. Off by default; each one changes how the game plays.
Every chair has to be taken before the game can start — by a person or by a bot. Pick the size of the table now; it cannot change once the game is created.
Ask whoever created the game for its code.
They enter it under Join a game, along with the same join secret you used.
The host may fill an empty seat with a bot, and starts the game once every seat is either a player or a bot. These chairs are not the running order — who sits where along the Division is decided by a D12 roll when the game starts (§4.4), and the map shows the result.