1NT Opening

General

The opening bid of 1NT promises 11-14 HCP, or 15 HCP and less than 9 AKQ controls and a balanced hand that denies a four-card major suit. An artificial game-force relay is employed after a puppet to 2D, as are more conventional transfer sequences, and some preemptive bids utilising the minor-suit orientation of the opening bid.

Responses to 1NT

2C	Puppet to 2D
	2D	Forced
		P	to play
		2H	GF relay (continuations as after 1C 2D)
		2S	GF, 5+S
			2N	doubleton S
				3m/3H	splinter
				3S	6S, choice of contracts
				3N	to play
				4m	5S4M22, slam INV needing fitting honours (else relay)
			3m/3H	3S, antiSPL (i.e. values that would be wasted opposite a SPL)
				Responder's continuations are Qs
		2N	Min GF, bal(ish)
			3C	2=3=x=y
			3D	3=2=x=y
			3H	3=3=(34)
			3N	3=3=(25)
		3x	splinter, <5M
2D	5+H
	2H	almost all hands
		2S	artificial, GF.  Continuations as after responder shows 5+S GF
		2N	INV
		3m	INV, usually 55
		3H	INV, 6+H
		3S/4m	SPL, 6+H, slam INV
	2S/2N(=D)/3C	super max, 3H, antiSPL
		Now responder bids 3D to retransfer (later bids are Qs), shows a SPL or bids 3H (forcing) to be declarer and asking for Qs

2H	5+S, continuations as after TFR to hearts
2S	INV in NT, C or D
	2N	reject INV in NT
	3C	reject INV in C, accept in NT
	3D	reject INV in D, accept in NT and C
	3N	accept all INV
2N	minors, at least 54, may be weak
	3m	preference
		3M	SPL
		3N	2=2=(54), weak majors
3x	preemptive

Competitive Bidding

The opponents double for penalties

1N (X) 	P   to play
	XX  forces 2C
		2C  forced
			P   5+C
			2D  5+D
			2H  5+H
			2S  5+S, <10 points
	2C  4+C and 4-5 other
	2D  4+D and 4-5 M
	2H  4-5H and 4-5S
	2S  5-6S, 10-12 points
	2N  either
	    (1) 4+C and 4+D, 9+cards in minors, <GF (pass opener's 
	    minor-suit preference
	    (2) GF two suiter, at least 5 cards in each suit (bid 
	    cheaper suit)
	3x  6+X, <GF
	

The opponents double to show an unknown single suiter or other hand without a known 5+card suit

1N (X)	P   to play if advancer passes
	XX  12+points, F2N
	2C  as per 3.1
	2D  5+H (continuations as per 8.3 except that 2N shows 5H BAL)
	2H  5+S (continuations as per 8.4 except that 2N shows 5S BAL)
	2S  5-6S, UNB, INV
	2N  4+C and 4+D, 9+cards in minors, <INV or GF (rebid 2+card M)
	3x  6+x, <INV
	

The opponents show a suit naturally, possibly with another unknown suit

1N (2C)	X   penalties
	2x  5+x, <12 points
	2N  Stayman, GF
		3C  no stopper in C
			3D  5=4=x=y or 4=5=x=y
				3H  relay
					3S  4=5=x=y
					3N  5=4=x=y
			3M  4oM, <4M
			3N  4=4=x=y, stopper in C
			4C  4=4=x=y, no stopper in C
		3D+ stopper in C
	3C  6+D, INV+ or 5D, GF
	3D  5+H, INV+
	3H  5+S, INV+
	3S  GF, no stopper in C
	4m  TFR->H/S
	4M  to play

1N (2D)	X   penalties
	2x  5+x, <12 points
	2N  6+C, to play or 5+C, GF
	3C  Stayman, GF
		3D  no stopper in D
			3M  4oM, <4M
			3N  4=4=x=y, stopper in D
			4C  4=4=x=y, no stopper in D
		3M  4M, stopper in D  
	3D  5+H, INV+
	3H  5+S, INV+
	3S  GF, no stopper in C
	4m  TFR->H/S
	4M  to play 

1N (2H)	X   penalties
	2S  5+S, <12 points
	2N  One of:
	    (1) 4+C, 4+D, 9+cards in the minors, <12 points (pass 3m
	    preference)
	    (2) 6+D, <12 points (bid 3D if necessary)
	    (3) 4+C, 4+D, 9+cards in the minors, GF (rebid 3H)
	    (4) 6+D, GF (rebid 3S)
	    (5) GF, <4S, <6m, no stopper in H (rebid 3N)
	3C  6+C, <12 points
	3D  5+S, INV+
		3H  GF, asking for H stopper
		3S  2-4S, NF
		3N  GF, 2-3S, stopper in H
		4C  first stop, GF, 3+S
	3H  4S, GF
		3S  <4S, asks for a H stopper
		3N  <4S, H stopper
		4C  first stop, 4S, <14 points
		4D  4S, 14+points, antiSPL
		4H  4S, 14+points, antiSPL
		4S  4S, 14+points, no antiSPL in D or H
	3S  6+C, GF
	3N  to play, stopper in H
1N (2S)	X   penalties
	2N  One of:
	    (1) 4+C, 4+D, 9+cards in the minors, <12 points (pass 3m
	    preference)
	    (2) 6+D, <12 points (bid 3D if necessary)
	    (3) 4+C, 4+D, 9+cards in the minors, GF (rebid 3H)
	    (4) 6+D, GF (rebid 3S)
	    (5) GF, <4S, <6m, no stopper in H (rebid 3N)
	3C  6+C, <12 points
	3D  5+H, INV+
		3H  2-3H, NF
		3S  GF, asking for S stopper
		3N  GF, 2H, stopper in S
		4C  first stop, GF, 3+H
			4D  last train, 
	3H  4H, GF
		3S  <4S, asks for a H stopper
		3N  <4S, H stopper
		4C  first stop, 4S, <14 points
		4D  4S, 14+points, antiSPL
		4H  4S, 14+points, antiSPL
		4S  4S, 14+points, no antiSPL in D or H
	3S  6+C, GF
	3N  to play, stopper in H
      

The opponents show a suit artificially

P   weak or length in their suit
	Subsequent bid of their possible 4-card suit at the two level 
	is natural
X   balance of power
	Subsequent doubles are penalties over the length and 
	cooperative under the length
Q   takeout
other  as for a natural bid of that suit
	

The opponents double 2C

P   C stopper/4+C
	XX  to play
	2D  Stayman
	other  as after 2d response without competition
XX  penalties
2D  <4M, <1 C stopper
2M  4M, <1 C stopper
	

The opponents double 2D/2H

P   2M
XX  (2H, 5D) or 4H
2M  3M
other  as without interference
	

The opponents overcall 2D/2H

P   nothing to say
	X   takeout (subsequent NS is GF)
	NS  competitive
X   penalties
NS  3-4M, antiSPL