In Boston and Solo Whist there are no penalties for cards exposed by the single player, because he has no partner to take advantage of the information.

21. All cards liable to be called must be placed and left face upwards on the table. A player must lead or play them when called, provided he can do so without revoking. The call may be repeated at each trick until the card is played. A player cannot be prevented from leading or playing a card liable to be called; if he can get rid of it in the course of play, no penalty remains.

In Boston and in Solo Whist, if the exposed card is a trump, the owner may be called upon by his adversary not to use it for ruffing. If the suit of the exposed card is led, whether trump or not, the adversary may demand that the card be played or not played; or that the highest or lowest of the suit be played. If the owner of the exposed card has no other of the suit, the penalty is paid.

Penalties must be exacted by players in their proper turn, or the right to exact them is lost. For instance: In Solo Whist, A is the proposer, B the acceptor, and B has an exposed card in front of him. When Y plays he should say whether or not he wishes to call the exposed card. If he says nothing, B must await Z’s decision.

22. If a player leads a card better than any his adversaries hold of the suit, and then leads one or more other cards without waiting for his partner to play, the latter may be called upon by either adversary to take the first trick, and the other cards thus improperly played are liable to be called; it makes no difference whether he plays them one after the other, or throws them all on the table together, after the first card is played, the others are liable to be called.

23. A player having a card liable to be called must not play another until the adversaries have stated whether or not they wish to call the card liable to the penalty. If he plays another card without awaiting the decision of the adversaries, such other card also is liable to be called.

LEADING OUT OF TURN.

24. If any player leads out of turn, a suit may be called from him or his partner, the first time it is the turn of either of them to lead. The penalty can be enforced only by the adversary on the right of the player from whom a suit can be lawfully called.

If a player, so called on to lead a suit, has none of it, or if all have played to the false lead, no penalty can be enforced. If all have not played to the trick, the cards erroneously played to such false lead are not liable to be called and must be taken back.

In Boston, if the adversary of the bidder leads out of turn, and the bidder has not played to the trick, the latter may call a suit from the player whose proper turn it is to lead; or, if it is the bidder’s own lead, he may call a suit when next the adversaries obtain the lead; or he may claim the card played in error as an exposed card. If the bidder has played to the trick the error cannot be rectified. Should the bidder lead out of turn, and the player on his left follow the erroneous lead, the error cannot be corrected.