Terminology
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1. Two domino are said to Match if they can be oriented so the pip
value on the touching ends of the dominos are the same.
2. A Train is a sequence of dominos such that each pair of adjacent
dominoes Match.
3. A Double domino is a domino with identical pip values on both ends.
Double dominos play a special role in this game.
4. All Trains originate from a Double domino in the Hub at the center
of play.
5. The head of each Train is a domino that Matches the domino in the
Hub. The tail of the Train is a domino with one matched end. The
unmatched end of the tail is considered the free end.
6. A given domino is considered Playable if it Matches the free end
of the domino on the tail of one of the Trains avaiable to that
player.
7. Each player has their own Train and there is at most one communal
"Mexican Train".
8. At any point in the game, a player's own Train is either marked as
being Public or it is considered Private.
Starting Player
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9. Play begins with all players selecting a single domino from the
bone-pile. The player drawing the domino with the largest total
pip value is the starting player. If two players tie, the dominos
are returned to the bone-pile and a run-off drawing is performed
among the tied players until a single player has been selected as
the initial starting player.
10. The starting player is the player designated to attempt to open
the Hub.
Opening the Hub
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11. The designated starting player selects the largest Double from
their hand and places it in the Hub. If the designated player
does not have a Double, they must draw a domino and, if it is a
Double, it is placed in the Hub. If it is not a Double, the
starting player designation moves to the player to their left and
play continues until a Double has been found and placed in the
Hub.
12. In subsequent rounds of play, the starting player designation
begins with the player to the left of the player who successfully
opened the Hub in the previous round.
Taking Turns
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13. Play proceeds in turns, starting with the player who successfully
opened the Hub, and proceeding to the left.
14. During each turn, a player must consider the dominos in their
hand. If they hold one or more Playable dominoes, they must make
one of those Plays.
15. If a player holds no Playable dominoes, they must draw one domino
from the bone-pile. If that domino is Playable, they must
immediately Play it.
XX. If a player realizes, or a player's Play reveals that, in one or
more previous turns, that player drew and passed rather than play
a Playable domino, the offending player must immediately draw one
domino from the bone-pile for each player that has taken a turn
since the offending player's previous actual Play.
16. Once all options for Play have been exhausted, the turn proceeds
with the player to their left.
Starting Trains
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17. A player must start their own Train before Playing on a Public
Train or the Mexican Train. A player's Train is considered
Private until it has been started. ie: No player can start another
player's Train.
18. A player is, however, still responsible for Covering Doubles, even
if they have not started their own Train. (see: Doubles)
19. A player starts a Train by Playing a domino against the Hub that
Matches the Double therein. On the turn in which they start their
own Train, a player may Play as many dominos as they can Match on
their own Train.
20. Once their own Train has been started, a player may use a
subsequent turn to Play a single Matching domino to start a
Mexican Train if one does not already exist. There can be only
one Mexican Train.
All Aboard
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21. A discretionary turn is one in which there are no Trains with
uncovered Doubles.
22. On each discretionary turn, a player may choose to Play one domino
either on their own Train, on any marked Public Train, or on the
Mexican Train (which is always considered Public).
23. If, on a discretionary turn, a player does not Play a domino on
their own Train, their Train must be marked as Public.
24. As soon as a player Plays on their own Train it becomes Private
unless the Play involves an uncovered Double.
Doubles
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25. When a Double is Played on a Train, Covering the Double becomes
the immediate priority of all players.
26. A Double is considered "Covered" when another domino that Matches
it is Played on that Train.
27. The player who Played the Double has the responsibility to Cover
it immediately during that same turn. If that player cannot
immediately cover the Double, the responsibility to cover the
Double passes to each player in turn until the Double is covered.
Such turns are considered non-discretionary
28. If a player Plays a Double on their own Train but is not able to
to immediately cover it, their Train is marked as Public.
29. If a player covers a Double on their own Train, their Train
becomes Private.
30. If a player is responsible for covering a Double that they did not
Play that is not on their own Train, the state of that player's
own Train remains unchanged regardless of whether the player is
able to Cover the Double. In other words: If a player has a
Private Train and is responsible for Covering a Double that they
did not play on the Mexican Train, their Train will remain Private
whether or not they are able to Cover the Double.
31. If a player draws a Playable Double as part of their turn but they
cannot Cover it out of their existing hand, they do not draw again
in an attempt to cover it.
32. If a player's last domino is a Playable Double, the player must
play it and then draw to attempt to cover the Double.
33. If the round ends with an unmatched Double domino, the player who
Played the Double is charged with the value of the Double domino.
Suspension
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34. A player that must draw to complete their turn (either because
they have no Play in their hand or because they played an
uncovered Double from their hand) but cannot because the bone-pile
is empty is Suspended. Their Train is marked as Public and they
may not make any more discretionary Plays during their turn until
the round is over. Such players must, however, Cover a Double, if
possible, when it is their responsibility.
Rounds End
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35. As soon as a player Plays all of the dominos in their hand and all
Doubles are Covered or as soon as all players are Suspended the
round ends and points are accumulated based on the pip totals in
each players hands and, possibly, any uncovered Doubles.