Responses

After a 1H/1S opening, partner must respond with 6+ points. Partner also responses in case of a weak hand and trump fit.

Response	Meaning after 1H opening	Meaning after 1S opening
1S	4+ cards, 6+ points (follow-up)
1NT	6+ points (forcing 1NT)	6+ points (forcing 1NT)
2C/2D	13+ points, 4+ cards, denies 3 hearts and denies 4 spades (follow-up)	13+ points, 4+ cards, denies 3 spades and denies 5 hearts (follow-up)
2H	6-9 points, 3+ cards	13+ points, 5+ cards, denies 3 spades (follow-up)
2S	9+ points, 6+ cards, denies 3 hearts	6-9 points, 3+ cards
2NT	11-12 points, balanced*, denies 3 hearts and denies 4 spades	11-12 points, balanced*, denies 3 spades and denies 4 hearts
3C	13+, 4 spades, 0 heart (better minor)	9-12 points, exactly 4 hearts, 0-1 spade (!!)
3D	13+, 4 spades, 0 heart (better minor)	9-12 points, exactly 5 hearts, 0-1 spade (!!)
3H	usu. 0-7 points, 4+ cards	9-12 points, 6+ hearts, 0-1 spade
3S		usu. 0-7 points, 4+ cards
4 of opening suit	usu. 3-9 points, usu. 5+ cards	usu. 3-9 points, usu. 5+ cards

* A singleton in the opening major is acceptable.

The following is a priority list in choosing a response:

• Bid 2 of the opening suit to show 6-9 points with trump support (could be followed by invitation to game or Blackwood or HSST)
• Bid 3/4 of the opening suit to show a weak hand and good trump support (could be followed by Blackwood or HSST)
• (Only for 1H opening) Bid 1S to show 4+ cards, or 2S to show 9+ points and 6+ cards (continuations)
• Make a two-over-one bid (preference in major, then better minor) to show 4+ cards with 13+ points (continuations)
• (Only for 1S opening) Bid 3C/3D/3H to show 4/5/6+ hearts with 9-12 points and short (0-1) spades
• Bid 2NT with 11-12 points and no trump support (continuations) (could be followed by Gerber)
• Bid 1NT with anything else and 6+ points (continuations)

Note that in case of 1H opening, showing trump support has priority over showing 4 spades with 6-9 points, but with 10+ points the spade suit should first be shown via 1S. Bid 2S only with 9+ points and 6+ spades and no trump support; in case of 6-8 points with 6+ spades and no trump support, bid 1S.
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.