“ Similarly a player who holds the ace of trumps must rob, putting out any card and taking in the turn-up, but need not disclose the fact till it is his turn to play. A player who fails to rob cannot go out that hand. The card put out may not be seen. The player on the dealer's left leads. The highest card of the suit led—the value of the cards will be explained—or the highest trump, wins the trick. Players must follow suit to a lead of trumps, except in certain cases which will be mentioned. To a plain suit no one need follow except a player who holds no trumps ”