If you find one of the adversaries without a trump, you should mostly proceed to establish your long suit, and abstain from drawing two trumps for one; to say nothing of the probability that the adversary who has not renounced is unusually strong in trumps. Besides, when he has the lead, he will very likely lead trumps in order to draw two for one; and it is more advantageous to you that the lead should come from him. On the other hand, if your partner has no trump, it is often right to endeavour to weaken the adversaries by continuing even their trump lead.
It is a common artifice, if you wish a trump to be led, to drop a high card to the adversary's lead, to induce him to believe that you will trump it next round, whereupon the leader will very likely change the suit, and perhaps lead trumps. Thus, if he leads king (from ace, king, and others), and you hold queen and one other, it is evident that you cannot make the queen. If you throw the queen to his king, he may lead a trump to prevent your trumping his ace; but if he goes on with the suit, and you drop your small card, it may fairly be inferred that you have been endeavouring to get him to lead a trump. Your partner should now take the hint, and, if he gets the lead, lead trumps; for if you want them led, it is of little consequence from whom the lead comes. By a conventional extension of this system to lower cards it is understood that, whenever you throw away an unnecessarily high card, it is a sign (after the smaller card drops) that you want trumps led. This is called asking for trumps or calling for trumps.
When you ask for trumps, you command your partner to abandon his own game, and to lead a trump; and you promise him, in return, if he has reasonably good cards, either to win the game or to make a considerable score. It has been laid down, that the minimum strength in trumps which justifies you in issuing such an order to your partner is four trumps, two being honours, or five trumps, one being an honour, accompanied by such cards in your own or your partner's suits that you are reasonably secure of not having a suit brought in against you. This rule, however, only applies to an original ask. If you have had the lead, and have not led a trump, or if you have had an opportunity of asking and have not asked, and you then ask for trumps at a later period of the hand, the ask is not a command, like an original one, nor does it necessarily imply the possession of the minimum strength above stated. It merely means that, from the fall of the cards, you consider a trump lead would be very advantageous. For example: you hold ace and a small spade; king, ten, and two small hearts (trumps); queen and two small clubs; and knave, ten and two other diamonds. You lead a small diamond; your partner plays the queen; the fourth hand plays the ace. A small club is now led through you. You should ask for trumps.
When your partner asks for trumps, and you have four or more at the time you obtain the lead, lead the smallest, unless you have the ace, or three honours, or queen, knave, ten; if you have only two or three trumps when you obtain the lead, lead from the highest downwards, whatever they are.
Before answering the ask, be sure that the higher card, previously dropped, is unnecessarily high. For instance a higher card is often played before a lower, to show that you command the suit, or that you hold the intermediate cards, or to get out of your partner's way. It is very important to distinguish between covering second hand and discarding an unnecessarily high card. For example: with knave, ten, and one other (say the three), it is usual to play the ten second hand on a small card. When your three comes down in the next round, it is not an ask for trumps, unless your partner can infer that you do not hold the knave. Moderate players, who know of the ask, never consider this; so with them the choice of the least evil is generally not to cover, for you otherwise run the terrible risk of having a strengthening trump led to you with a weak hand. To ask for trumps, second hand, with knave, ten, and one other, you must play the knave.
When your partner leads a trump, or asks for trumps, if you have numerical strength in trumps, you should ask at the first opportunity. This is called the echo of the call, though it is made use of also in response to a lead.
The advantages of the echo are manifold. Your partner being strong in trumps may hesitate to take a force, but your echo enables him to do so without fear, and to persevere with the trump lead. Or, your partner may be in doubt after the second round of trumps as to the policy of playing a third. But if he can count two more trumps in your hand he will be directed. Thus: eight are out, your partner has three more; you have echoed. He will know that the other two are in your hand, and will not draw two for none, as without the echo, he might do.
The negative advantage of the echo should not be overlooked. Thus: to take the same case of eight trumps being out, and the leader with three more trumps. You (his partner) have had the chance of sounding an echo, but have not done so. The leader knows that you have not both the remaining trumps, and he will regulate his game accordingly.
To your partner's trump lead you echo in the trump suit; the same if partner calls, and you are forced. Thus: you have eight, seven, five, two of trumps; your left-hand adversary leads king, ace of a suit of which you only hold one. Your partner calls. You echo, by trumping with the five, and you then lead the eight. On the second round of trumps, when your deuce falls, the echo is completed. Your partner knows that you have one more trump, either the six or the seven. If you had not echoed, he might not be able to tell for certain whether you hold another trump or not. (See Hands XXXIV., XXXV.)
If you have four trumps and are forced, and your partner then leads or asks for trumps, you should echo, notwithstanding that you no longer have numerical strength. This case can best be illustrated by an example. (See Hand XXXVI.)