2d. Any card dropped with its face upward, or in any way exposed on or above the table, even though snatched up so quickly that no one can name it.
3d. Every card so held by a player that his partner can see any portion of its face.
71. A card dropped on the floor or elsewhere below the table is not an exposed card.
72. If two or more cards be played at once, by either of the dealer’s adversaries, the dealer shall have the right to call which one he pleases to the current trick, and the other card or cards shall remain face upward on the table and may be called at any time.
73. If, without waiting for his partner to play, either of the dealer’s adversaries should play on the table the best card or lead one which is a winning card, as against the dealer and dummy, or should continue (without waiting for his partner to play) to lead several such cards, the dealer may demand that the partner of the player in fault, win, if he can, the first, or any other of these tricks, and the other cards thus improperly played are exposed cards.
74. If either or both of the dealer’s adversaries throw his or their cards on the table face upward, such cards are exposed and are liable to be called; but if either adversary retain his hand he cannot be forced to abandon it. If, however, the dealer should say, “I have the rest,” or any other words indicating that the remaining tricks are his, the adversaries of the dealer are not liable to have any of their cards called should they expose them, believing the dealer’s claim to be true, should it subsequently prove false.
75. If a player who has rendered himself liable to have the highest or lowest of a suit called (Laws 82, 91, 92 and 100), fail to play as directed, or if, when called on to lead one suit, lead another, having in his hand one or more cards of the suit demanded (Law 76), or if called upon to win or lose a trick, fail to do so when he can (Laws 73, 82 and 100), he is liable to the penalty for revoke, unless such play be corrected before the trick is turned and quitted.
LEADS OUT OF TURN
76. If either of the dealer’s adversaries lead out of turn, the dealer may call the card erroneously led, or may call a suit when it is the turn of either adversary to lead.
77. If the dealer lead out of turn, either from his own hand or dummy, he incurs no penalty; but he may not rectify the error after the second hand has played.