Responses

After a 1C/1D opening, partner must respond with 6+ points, which forces to 1NT. Partner also responses in case of a weak hand and trump fit.

Response	Meaning after 1C opening	Meaning after 1D opening
1D	5+ cards, 6+ points, denies 4-card major
1H	4+ cards, 6+ points	4+ cards, 6+ points
1S	4+ cards, 6+ points	4+ cards, 6+ points
1NT	6-10 points, balanced, denies 4-card major	6-10 points, balanced*, denies 4-card major
2C	IMR -- 9+ points, 5+ cards, denies 4-card major	4+ cards, 13+ points, denies 4-card major
2D	6+ cards, 9+ points, denies 4-card major	IMR -- 9+ points, 4+ cards, denies 4-card major
2H	6+ cards, 9+ points	6+ cards, 9+ points
2S	6+ cards, 9+ points	6+ cards, 9+ points
2NT	11-12 points, balanced, denies 4-card major	11-12 points, balanced*, denies 4-card major
3 of opening suit	usu. 0-7 points, usu. 6+ cards	usu. 0-7 points, usu. 5+ cards
3NT	13+ points, balanced, denies 5-card major	13+ points, balanced*, denies 5-card major
4C	Gerber	Gerber
4NT	Blackwood	Blackwood

* A singleton in diamond is acceptable.

The following is a priority list in choosing a response:

• Bid 2H/2S to show a 6-card major with 9+ points (continuations)
• Bid 1H/1S to show a 4-card major (continuations)
• (Only for 1C opening) Bid 1D to show a 5+ cards (continuations)
• (Only for 1D opening) Bid 2C to show a 4+ cards with 13+ points (continuations)
• Bid 2 of the opening suit to show 9+ points and trump support (continuations)
• Bid 3 of the opening suit to show a weak hand and good trump support (continuations)
• Bid 1NT/2NT/3NT to show a balanced hand without a 4-card major (continuations)
• Explore slam via Gerber or Blackwood in case of a very strong balanced hand

A jump by opener in the second bid shows 17+ points, while a jump by responder in the second bid shows 11+ points. Either jump usually forces to game unless the other side holds a very minimum hand.