Kepler & K2 provide long-baseline, high-precision photometry for exoplanet and astrophysics research.
The basic and most common additional rule for Doubles play is that where a Double exists at the end of any train, the Double must then be 'satisfied' (laid against) in the next turn, even if the Double is on another player's train that is not marked.
1 Any player without a train must continue to pick up dominoes until he either draws a domino with a 12 (engine) or can place a domino on a Mexican train that another opponent has started. 2  No player is allowed to play on another player's train, nor to start the Mexican train, during their first turn.