When 0 on the rubber game.
The dealer should NOT declare clubs
Unless his score is 18 or more points, and the hand strong enough to win the game.
The dealer should NOT declare spades
Unless his score is 24 or more points, and the hand strong enough to win the game.
PASSED MAKES
The dummy hand, in declaring the trump, should keep in mind the rules suggested for the dealer, and, at the same time, be governed in his choice by the state of the score, by the general strength of his hand, and by the dealer's acknowledged weakness. When the make has been passed, one must infer that the dealer has not a strong hand, neither has he much strength in the red suits. While the latter inference may be doubtful, the dealer often passing a fair diamond hand, it is dangerous to declare no-trump without protection in the red suits, and the declaration may result in a disastrous loss.
The following suggestions may prove useful:
The fact that your hand is exposed gives the adversaries an opportunity to take advantage of its weak points.
A no-trump make that is weak in the red suits, unless justified by the score, is unsound.