Undergrowth Pai Sho is a tile placement game based on the Skud Pai Sho harmony system.
On Host’s first turn, they place a tile in a Gate.
On Guest’s first turn, they place two tiles in open Gates.
On Host’s second turn, they fill the remaining Gate and play one tile elsewhere on the board.
After these initial turns, a player’s turn consists of placing two tiles onto the board. When placing a tile onto the board, place a tile onto the board on any space where a) the tile forms Harmony with the player’s own tile(s) and b) the placed tile does not interrupt an existing Harmony or Disharmony on the board. A player may also pass if they have no available moves.
After a tile is placed, remove any tile with two or more Disharmonies from the board.
After the last piece is played or both players pass in succession, the game ends. The player with the most tiles in or touching the Central Gardens on the board wins.
Other rules:
- Same/alike tiles form Disharmony, as in Overgrowth.
- Tiles in Gates can form Harmony with friendly tiles that are not also in Gates, but do not form Disharmony.
- The Orchid harmonizes with all friendly Flower Tiles, but also forms Disharmony with everything at the same time.