Underground is a single 4 dice expansion. Manage an underground network of Subways and Water Pipes. You can use the Underground dice either as an Expansion to the base game or as a standalone game.
To play with the Underground dice as an Expansion, you need two boards for each player: one board for the Surface and one for the Underground. You will play alternating between Surface and Underground rounds for a total of 14 rounds: 7 Surface rounds and 7 Underground rounds. Start with a Surface round, following the normal rules of the Railroad Ink version whose boards you chose as the Surface boards.
During an Underground round, the Underground dice are rolled and every player must draw the results of these dice on their Underground board, following the Underground placement restrictions.
INTERACTION BETWEEN SURFACE AND UNDERGROUND
The the two boards interact in two ways: you can create Hubs and gain points by matching the positions of Subway Stations and surface Stations; additionally, you will break a pipe and lose points if you draw a surface Station above a Water Pipe space.
Creating a Hub: If a surface Station and an underground Subway Station share the same space, fill the Subway Station: it is now a Hub.
Breaking a Pipe: Drawing a Station “on top” of a pipe will break it, but not vice-versa.
STAND ALONE VARIANT
When playing the Standalone version, you only play with the Underground board. Follow the rules of the Expansion Mode with just a few changes:
- Play only for 7 rounds.
- Don’t use a Surface board and the white Route dice.
- Ignore all the interaction rules between the Surface and Underground boards.
- When you draw a Subway Station, if there is no Hub in the same row and/or column, you must immediately transform that Subway Station into a Hub.