3.2 Rebids After Opening 1♣

After you open 1♣ and partner responds 1♦, you are in a unique position. You know partner does not have a major suit unless she has game-going values, so you don’t need to show your major suit with a balanced hand. This can provide a real tactical advantage by “hiding” the major suit distributions from the opponents.

West	North	East	South
	1♣	Pass	1♦
Pass	?

1♥	4+ Hearts, unbalanced hand
1♠	4+ Spades, unbalanced hand
1NT	12 - 14, balanced hand, might have 4M
2♣	Ususally 6+ clubs
2♦	4+ diamonds, unbalanced hand
2♥	4+ Hearts, game force
2♠	4+ Spades, game force
2NT	18-19 HCP, balanced hand
3♣	6+ clubs, at least AJ10xxx 16 - 18
3♦	4+ diamonds, 16 - 18, unbalanced hand
3♥	4+ diamonds, small singleton heart, 19+
3♠	4+ diamonds, small singleton spade, 19+
3NT	6+ clubs, 8 - 8-1/2 tricks (not a balanced hand)
4♣	Unused
4♦	RKCB for diamonds

West	North	East	South
	1♣	Pass	1♦
	1♥		?

1♠	4+ Spades, game force (with less you would have bid 1♠ in the first place, not 1♦)
1NT	Spade stopper, 6 - 10
2♣	3+ clubs, no spade stopper, 6-10
2♦	6+ diamonds, no spade stopper, 6 - 10
2♥	4+ hearts, game force (with less you would have bid ♥ in the first place, not 1♦)
2♠	0 - 3 spades, 0 - 3 hearts, game force (Fourth Suit Forcing)
2NT	Spade stopper, 10-12 HCP
3♣	3+ clubs, no spade stopper, 10 - 12
3♦	6+ diamonds, 10 - 12
3♥	Good diamonds and hearts, xx in spades and clubs, game force
3♠	4+ Hearts, small singleton spade, slam-try
3NT	13 - 15 balanced, denies 4M

West	North	East	South
	1♣	Pass	1♥
Pass	?

1♠	4+ spades, could be a balanced hand, but not 4=3=3=3
1NT	12 - 14 HCP, balanced hand, denies 4 spades unless 4=3=3=3
2♣	Ususally 6+ clubs, minimum range
2♦	4+ diamonds, usually 5+ clubs, Reverse, 17+ HCP, promises a rebid
2♥	3+ hearts if unbalanced 6 - 7 losers or 4 hearts if balanced, 12 - 14
2♠	4+ spades, usually 5+ clubs, Jump Shift, game force
2NT	18-19 HCP, balanced hand, does not deny 4 spades
3♣	6+ clubs, at least AJ10xxx 16 - 18, denies 4M
3♦	4+ hearts, small singleton diamond, game force
3♥	4+ hearts, 18 - 19 HCP if balanced, otherwise 5-loser hand
3♠	Small singleton spade, 4+ hearts, game force
3NT	6+ clubs, 8 - 8-1/2 tricks (not a balanced hand)
4♣	6+ clubs, 4+ hearts, 19+ in support
4♦	Unused
4♥	4+ hearts, unbalanced hand, 19+ in support, not suitable for a splinter

West	North	East	South
	1♣	Pass	1♠
Pass	?

1NT	12 - 14 HCP, balanced hand
2♣	Ususally 6+ clubs, minimum range
2♦	4+ diamonds, usually 5+ clubs, Reverse, 17+ HCP, promises a rebid
2♥	4+ hearts, usually 5+ clubs, Reverse, 17+ HCP, promises a rebid
2♠	if unbalanced, 3+ spades, 6 - 7 losers; or if balanced, 4 spades, 12 - 14
2NT	18-19 HCP, balanced hand, may have 4M
3♣	6+ clubs, at least AJ10xxx 16 - 18, denies 4M
3♦	Singleton diamond, 4+ spades, game force
3♥	Singleton heart, 4+ spades, game force
3♠	4+ spades, 18 - 19 HCP if balanced, otherwise 5-loser hand
3NT	6+ clubs, 8 - 8-1/2 tricks (not a balanced hand)
4♣	6+ clubs, 4+ spades, 19+ in support
4♦ - 4♥	Unused
4♠	4+ spades, unbalanced hand, 19+ in support, not suitable for a splinter

Note

This structure assumes you do not raise responder’s Major suit response with 3 trump. That’s not a recommendation, just one way to do it. You can use essentially the same structure and still raise with 3 trump and a ruffing value.