OVERVIEW: The domino game 42 is similar in strategy to the card game Bridge; however, it is not as complicated. Some folks say 42 (also called Texas 42) was conceived by a lad in east Texas because his parents would not let him play cards; others say 42 originated in Georgetown (central Texas). The most widely publicized story, however, says 42 started in Garner, Texas in 1887 (see Q/A30). The rules discussed in this document reflect the game as played by and taught to me by friends in the south Texas town of Devine.
Forty-two (42) is played by four people. A set of double-six dominos is required. Players sitting opposite each other
are partners. The dominos are shuffled face down. Players
draw seven (7) dominos apiece at random (shuffler draws last) and conceal the dot (pip) sides from
each other. Each player "bids his/her hand" in rotation. The highest
bidder may designate a trump suit and begins play by leading a domino.
Each player, in turn, must follow the suit led (if possible); otherwise he may play any domino in his hand. The person
playing the highest domino in the suit led takes the trick and leads the next domino. (If played, the highest trump takes any trick.)
This process continues until all 28 dominos are played, the bid is made,
or the high bidder is "set." Partners work together (without "talking
across the table") to make their bid or to set the opposing team.
THE PLAYERS: Who will be partners
is determined by mutual agreement or by drawing dominos. When drawing,
the dominos are shuffled and each player draws a domino. The player
who draws the highest domino will be the scorekeeper, and the next highest
domino holder will be his partner. The two lowest domino holders
will be the opposition partners. In case of tie(s), those players
each draw another domino to break the tie. Partners sit opposite
each other at the table.
THE SHUFFLE: All 28 dominos are
shuffled face-down. The scorekeeper shuffles the dominos to start
the game. Thereafter, the shuffle rotates to the left (clockwise)
after each "hand" has been played. If multiple games are played at
one sitting, and the same partners are retained, then either of the previous
winning player partners shuffle to begin a new game.
BIDDING: The player to
the left of the shuffler begins the bidding. He may bid or pass (not
bid). The bid rotates left (clockwise) to the next player until all
have had an opportunity to bid. Each bid must be higher than any
preceding bid(s). If all players pass, the dominos are reshuffled by the next player and the bidding process repeated.
The minimum bid allowed is 30. Bids higher
than 41 must be in marks. The first bid in marks can be one or
two marks. Subsequent players may bid one mark more than previously bid. When one or more
marks are bid, the high bid partners must take (win) all seven tricks.
If they lose one trick, they are set, and the opposing team partners get
the mark(s) they bid. (Dominos with count value have no special significance
when the bid is one or more marks.)
OPENING PLAY: Following the bidding process, the high bidder declares a trump suit (or no trumps) and starts the hand by leading a domino. Each player, in turn (clockwise), must follow the suit led if possible. For example, if a is led, sixes (high end of the domino) is the suit led unless the high bidder had declared treys (threes) the trump suit. (See TRUMPS below for clarification.) The player who wins the trick leads the next domino. Scoring for each hand is recorded after all seven tricks are played or the high bidder is set (doesn't make his bid).
SCORING: Each trick is
worth one point. Dominos divisible by five (5) are worth their face
values, e.g., or is 10 points
and or is five
points. (The other three count-dominos are , , and .) There
are seven (7) tricks in a hand and five dominos with a total "count" value
of 35 points, hence the name 42 (7+35).
Each hand won is scored as a mark (or marks bid). If the bidding partner(s) do not make their bid (or higher),
the opposition partners get the mark(s). The partner team who score
seven marks first wins the game. Marks are recorded on paper by spelling "ALL." (Each letter segment is a mark.) Scoring by points is optional.
TRUMPS: Trumps are like a suit in cards. When declared, the trump suit outranks the other domino suits. If a player gets the bid and calls "treys" (threes) trump, then the seven dominos
with three dots (pips) on one end are trumps:
(double is highest), , , ,
(a five-count), ,
(lowest). Doubles may also be declared a trump suit. When a trump is led, each player must play a trump if he
has one. High trump wins any trick. If a non-trump domino is led, and a player cannot follow suit, he may (does not have to) play a trump if he has one.
NO TRUMPS: A player who gets the bid may elect no trump ("follow me"). When "follow me" is called, each player, in turn, plays the "suit" corresponding to the high end of the domino led in each trick. The double in each suit is high. A player may play any domino if he cannot follow suit. In any case, whoever wins a trick leads the next domino.
STRATEGY: If your bid is the highest, you have the advantage of calling trumps and leading the first domino. The object is to bid wisely, make your bid, or help your partner make his bid. If the opposing team partners get the bid, then you and your partner try to set them. This is done by preventing them from making their bid, if possible, by "catching" (winning) tricks with "count." (If the bid is in marks, you can set the opponents by taking any trick.)
For example, if an opposing player leads the double-five (fours are trump), and you do not have a five, you can play a four (trump) on your turn and win the trick (if nobody else "overtrumps" you). By winning the trick, you and your partner get 11 points (the trick plus the ten-count), or 16 points if the five/blank () is also played in the same trick (or you trumped-in with the four/ace ). This is sufficient to set a bid greater than 31 (42-11=31) or, with the additional five-count, set any bid (42-16=26).
When trying to make your bid, normally, you should call in the trumps (or try to find out where they are) by leading them early in the hand. You want to put count on tricks you and your partner take. When possible, you may want to take the lead to allow your partner to get rid of (unload) "off" dominos which would otherwise jeopardize making the bid. In this regard, knowing what to do comes with experience and playing the odds on domino distribution. It helps to keep track of which dominos have been played and which ones are still held. Sometimes luck and guesswork determine the outcome of a hand.
INDICATING: Many 42 players interpret a 30-bid to mean that the bidder has doubles and/or count dominos that could help his partner make a higher bid. In other cases, however, a 30-bid simply means that the bidder thinks 30 is the highest bid he can make.
Some players also try to indicate to their partners which doubles they're holding by what they play when they are unable to follow the suit led. The two most common practices are  playing the double itself to indicate they're holding the next highest domino in that suit, or  playing a domino whose high end indicates they're holding the double in that suit. (When more than one double is held, players usually indicate their highest doubles first if they can.)
Whereas the latter style for indicating doubles is frowned on by many "pure 42" advocates as being unwise, it is nonetheless commonly practiced and completely legal. Realistically, these common indicating styles cannot be legislated out of the game. Prearranged secret indicating and bidding signals between partners, however, are considered cheating.
"False indications" can occur, sometimes with undesirable results. Playing count or some other domino is often more prudent than indicating. Even without indicating, a bidder normally expects some kind of help from his partner, whether it's donating count or having an important double. In any 42 game, experience and observation skills are helpful to correctly interpret bidding practices and play action on the board.
PROTOCOL: Players agree on the rules before beginning a game. The shuffler draws his dominos last. The partner of the high bidder normally
gathers in the dominos at the end of each trick they take. The opposing
partner team gathers their own tricks taken and keeps them separate from
the other team's. The tricks are stored face up, off to the side
of the playing surface. When one or more marks are bid, the dominos
are stacked so only the last two tricks can be viewed (dot sides). (This makes domino tracking more dependent on players' memories.)
a player plays out of turn or reneges (fails to follow suit when able),
the hand is ended and the opposition partners get the mark(s). Once
a domino has been played, it cannot be retrieved (taken back). "Talking
across the table" about the hand in play is strictly prohibited. (Social chitchat is okay.) See Q&As 75, 74, 52, et al, for more.
SAMPLE HAND (with indicating): Nancy, Steve, Will
and Ella are from Austin. They play 42 every Friday night. Nancy
shuffles, and each draws seven dominos
(Nancy last). Ella bids first.
Domino faces exposed for demo purposes only
left of shuffler Nancy) begins the bid. She has four fives
she could call trump, but she doesn't have the double-five (a ten-count)
so she passes. (I would have bid 31 since I could afford to lose the
trick with the double-five; however, trying to get back in the lead to
"walk" my deuces would be risky. In this hand, Steve
has the double-five, would win the trick when it was played, and could
come back with his double-blank 
lead and set me.)
The bid rotates clockwise to Steve
has a good helping hand (three doubles). He bids 30 since he can indicate two of his doubles
to his partner. (If his partner passes and he ends
up having to take the bid for 30, he would probably call fours trump or
call no-trumps ["follow-me"] in hopes of making his bid. In this
case, unbeknownst to Steve, his partner [Nancy]
has the other three trumps if he called fours as trump. If Nancy/Steve
played their dominos wisely, they shouldn't have any problem making 30.)
Will is strong in treys and sixes, so he bids 31. If he gets the bid, he could call either treys or sixes as trumps. In this case, he wants to try sixes, hoping his partner has the six/four () trump, and/or it falls on the first trick when he leads the double-six (). (Treys might be a safer trump since the five/deuce  "off" domino makes Will more vulnerable to being set, especially if he didn't take in the six/four  trump in the first trick. In this case, Nancy would surely play her six/blank  on the first trick and then she would be holding the high trump [a ten-count] and the double-ace  for taking subsequent leads and setting Will.)
(last bidder) is strong in aces. Since her partner (Steve)
indicated he had a helping hand, she bids 32 and calls aces trump.
(Bidding more than 32 was not necessary since Nancy
had last bid, and the previous high bid was 31. If Nancy
would have had to bid higher than 32 to get the bid, she could have bid
as much as 35 without being set [as demonstrated below].)
↓ Note: Players' hands in mouseovers below are exposed for demo purposes only.
Trick #1: Nancy leads her highest trump (), and each player, in turn, follows suit by playing a trump. Nancy takes the trick.
the second highest trump () to call
in the other trump and, hopefully, get an indication from her partner
(Steve). Her partner cannot follow suit so he indicates
he has the double-five () by playing
the five-four ().
cannot follow suit, so he "throws off" the trey/blank ().
takes the trick.
Trick #3:Nancy does not have a five, so she cannot "come" to her partner by leading a five. Since Nancy has the
(a ten-count), it is relatively "safe" for her to lead the
(it won't draw the out).
Her partner cannot follow suit, so he indicates his double-four ()
by playing the . Ella
the trick with the . Her
partner (Will) could have taken the
trick with his , but decided
to save it in hopes of "catching" the
her double-deuce (), and everybody
follows suit. Ella takes
the trick which includes the five-count ()
that Nancy had to play.
the (a "walker" since the other
six deuces have already been played). Nancy
"trumps in" with the four/ace (),
a five-count, and takes the trick.
the so her partner can take
the lead (assuming the he played in Trick #3 was
not a false indicator). Her partner (Steve)
takes the trick with the double-four ().
the double-five () to take the last
trick and make the bid. Nancy
was able (fortunate) to play the
on this trick, and Ella had to play
the last five-count ().
get a mark on the score pad, and Ella
shuffles ("shakes") the dominos for the next hand.
GAME VARIATIONS: Non-tournament 42 may be played with variations not sanctioned by the National 42 Players Association (N42PA). For example, my house rules allow a bid to be twice as many marks as a previous high bid in marks. The forced bid Nel-O option is also popular among social players who enjoy a little twist in the game and don't like to reshuffle every time everybody passes:
GOING LOW (Nel-O): When the last player in the bidding process (the domino shuffler) has the bid "dropped" on him (everyone before him passed), he has to bid at least 30. He also has the option of bidding one or two marks "low." If he goes low, there are no trumps, his partner does not play (turns his dominos face-down), and he tries to take no tricks. He begins play by leading a low domino and hoping one of the opposing players takes the trick (and the lead). Doubles are a suit of their own. If a double is led, then doubles have to be played by the opposition if they have any. If he can stay out of the lead (take no tricks) for the remainder of the hand, he makes his bid. If, however, he takes one trick, the hand is ended, and the opposition partners get what he bid. Count-dominos have no special significance in Nel-O.
Forty-two (42) may also be played with other variations not discussed in this document, e.g., Plunge or Splash (bid four [or two] marks if four [or three] doubles held; partner calls trump and leads), Sevens, and Nel-O variations. Three-handed 42 (Moon) and six/eight-handed 42 (84 and 88) can also be played. More information is available via the following button: