Be nice to your partner.
Be courteous to your opponents.
And enjoy your bridge!
Opening Rule of 20
Looking for a NT game
East opens 1D (rule of 20) and West looks for a spade fit - he knows they have points for game between them. When East can only rebid diamonds (he is too weak to bid his hearts, that would be a reverse which shows a strong hand, 16+ points), West makes a forcing bid of 3C. East is now happy to bid 3NT as he has the hearts covered.
If South starts with QC, East covers and when the King wins he can see 9 certain tricks and can finesse the JH for a tenth.
Evaluating if enough for game
North opens 1C (rule of 20), South bids his suit and West has enough (5 card suit with 3 honours) to show his diamonds.
North is weak so supports partner’s spades rather than rebidding his clubs. East knows their side haven’t got most of the points but by going 3D he may push NS too high.
If South gets too excited and bids 4S it will go off provided that EW take their tricks (2 diamonds, 1 heart and the KS) before NS clear trumps and take their clubs