Suction Convention

Used in order to show single suited or double suited hands against 1 NT opennings

Opener	1st Opponent	Explanation
1 NT	2 Clubs 2 Diamonds 2 Hearts 2 Spades 2 NT	Long Diamonds or Spades and Hearts Long Hearts or Spades and Clubs Long Spade or Diamonds and Clubs Long Clubs or Hearts and Diamonds Spades and Diamonds or Hearts and Clubs

2nd opponent will bid adjacent higher suit. So, if the overcall is 2 Clubs, 2nd opponent will bid 2 Diamonds. 1st opponent pass with long Diamonds, otherwise bids 2 Hearts and waits for his partner's choise. There is a problem with the 2NT overcall, because if the 2nd opponent will bid otomatically 3 Clubs, then he could not show his choise. So, in this case, 2nd opponent should make his choise at this point. If he supports Clubs, then he bids 3 Clubs, otherwise he bids 3 Diamonds. If the both minors are less than 3 cards, then he bids 3 Hearts. In short, he bids his first at least 3 cards suit.

If you want, you can solve this problem by changing the places of the meanings of 2 Spades and 2 NT overcalls.

If the responder bid anything after overcall, then 2nd opponent passes.