1NT Forcing

1NT Forcing (aka the Forcing Notrump) is a cornerstone of the 2/1 ("Two Over One") bidding system. After partner opens 1/, a 1NT response shows 6-12 HCP and is a one-round force.

In standard bidding methods, a 1NT response shows 6-10 HCP. Playing 2/1, however, this range must be widened to include the game-invitational 11-12 point hands that are ineligible for a game-forcing 2/1 response. Note that a natural 2NT response is unavailable as well; it is reserved for the Jacoby 2NT convention that shows a game-forcing raise.

Examples of hands that would bid 1NT Forcing in response to 1:

Q52
93
A432
J987

     Balanced, 7 points. A 1NT response in any system.

K98
J5
532
AK986

     With 11 points, this hand is too weak to respond 2 in the 2/1 bidding system.

95
A52
54
T97652

     This one is a matter of partnership discussion. Some players like to stick crummy raises (4-5 points) into 1NT Forcing. In this case, responder plans to rebid hearts at the cheapest level.

K95
A52
K5
JT987
     1NT Forcing can also be used to show a 3-card limit raise with 10-12 points. In this case, responder plans to jump-raise hearts next.

Opener's Rebids

Frankly, this area is a weakness of the 2/1 system. A 1/ opening bid may be made on a wide variety of hand patterns between 11-20 points. Opener may not have a descriptive rebid available.

After 1 : 1NT

2 May be as short as two clubs, e.g. 4-5-2-2 shape with insufficient strength to make a 2 reverse.

2 May be as short as three diamonds, e.g. 4-5-3-1 or 3-5-3-2 shape.

2 Shows six hearts, may have a four-card side suit.

2 Shows four spades, rarely five if opener is 6-5 in hearts and spades. This is a reverse showing at least 16 points.

2NT Balanced, 18-19 points. Invites partner to bid 3NT.

All other bids are natural and/or a matter of conventional agreement.

After 1 : 1NT

2 May be as short as three clubs, e.g. 5-3-2-3 shape.

2 May be as short as three diamonds, e.g. 5-3-3-2 shape.

2 Shows at least four hearts and 11-15 points. Insufficient strength to jump-rebid 3.

2 Shows six spades, may have a four-card side suit.

2NT Balanced, 18-19 points. Invites partner to bid 3NT.

All other bids are natural and/or a matter of conventional agreement.

1NT Semi-Forcing

Because of opener's potential rebid problems, some partnerships play 1NT as "semi-forcing", meaning that opener can pass with a minimum balanced hand. Many experts including Larry Cohen and Kit Woolsey endorse this approach. Another popular agreement is to play 1NT as semi-forcing by a passed hand.

Responder's Rebids

After opener rebids 2

Pass At least four clubs (typically five), 6-10 points. Correcting to partner's major with doubleton support is preferable.

Any new suit A new suit at the 2-level shows at least five cards, and poor support for partner's major. Non-forcing.

2-major Signoff in partner's major, shows 2-card support or a very bad hand with 3-card support.

2NT Balanced, 11-12 points. Invites partner to bid 3NT.

3 At least four clubs, 11-12 points. Non-forcing.
3-major A 3-card limit raise.

After opener rebids 2

Pass At least four diamonds (typically five), 6-10 points. Correcting to partner's major with doubleton support is preferable.

Any new suit At least five cards at the 2-level, or six cards at the 3-level. Non-forcing.

2-major Signoff in partner's major, shows 2-card support or a very bad hand with 3-card support.

2NT Balanced, 11-12 points. Invites partner to bid 3NT.

3 At least four diamonds, 11-12 points. Non-forcing.
3-major A 3-card limit raise.

After opener rebids a major

Any new suit At least six cards, and poor support for partner (a singleton or void). Non-forcing.

2NT Balanced, 11-12 points. Invites partner to bid 3NT.

3-major A raise shows 2-card support with 10-12 points or 3-card support with 10-11 points. Invites partner to bid game.
4-major A 3-card limit raise, 11-12 points.

After opener reverses

These rebids are used when opener opens 1 and rebids 2.

2NT Balanced, showing 6-9 points. Non-forcing.

3/ At least six cards, non-forcing.

3 2-card support, or a very bad hand with 3-card support. Responder may have something as unsuitable as 2-2-5-4. Non-forcing.

3NT 10-12 points, balanced.

After opener rebids 2NT

Any new suit At least six cards. Note that this is less preferable to simply bidding 3NT.

3-major A very bad hand with 3-card support. Non-forcing.
3NT Signoff.

In Competition

If the opening 1/ bid is doubled or overcalled, then a 1NT response is natural, 6-10 points and non-forcing. Against an opposing takeout double, responder can redouble with 11-12 balanced points.

If 1NT is doubled, then the force is "off". Opener can make a natural rebid or simply pass with an awkward hand pattern like 3-5-3-2. Opener may also choose to redouble to show extra strength.

Examples

Opener Responder

KT93 AJ5

AKJ62 54

J3 K985

42 JT63

Opener
1
2 (2)
Pass

Responder
1NT (1)
2 (3)

1NT Forcing
Stuck for a bid. Lacking the strength to bid spades (and not playing Flannery).
Taking a preference. Raising clubs would promise game-invitational strength.

Opener Responder

AT9852 KJ

AK5 842

K42 AQ85

4 J963

Opener
1
2 (2)
4

Responder
1NT (1)
3 (3)
Pass

1NT Forcing
Natural, 11-15 points and at least six spades
Inviting game with doubleton support and a maximum

Opener Responder

QJT95 K2

AK54 QJT3

Q4 A853

65 976

Opener
1
2 (2)
Pass

Responder
1NT (1)
3 (3)

1NT Forcing
Natural, 11-15 points and at least four hearts
Four-card support and a maximum

Opener Responder

K8653 6

AK5 QJ6

Q4 AJT532

J65 972

Opener
1
2 (2)
Pass

Responder
1NT (1)
2 (3)

1NT Forcing
Stuck for a bid. Shows at least two clubs.
At least a five card suit, 6-10 points, non-forcing

Opener Responder

987 A62

AQ873 K54

AK4 Q763

JT K72

Opener
1
2 (2)
4

Responder
1NT (1)
3 (3)
Pass

1NT Forcing
At least three diamonds
A delayed jump raise, i.e. a 3-card limit raise

Q52 93 A432 J987		Balanced, 7 points. A 1NT response in any system.
K98 J5 532 AK986		With 11 points, this hand is too weak to respond 2 in the 2/1 bidding system.
95 A52 54 T97652		This one is a matter of partnership discussion. Some players like to stick crummy raises (4-5 points) into 1NT Forcing. In this case, responder plans to rebid hearts at the cheapest level.
K95 A52 K5 JT987		1NT Forcing can also be used to show a 3-card limit raise with 10-12 points. In this case, responder plans to jump-raise hearts next.

2	May be as short as two clubs, e.g. 4-5-2-2 shape with insufficient strength to make a 2 reverse.
2	May be as short as three diamonds, e.g. 4-5-3-1 or 3-5-3-2 shape.
2	Shows six hearts, may have a four-card side suit.
2	Shows four spades, rarely five if opener is 6-5 in hearts and spades. This is a reverse showing at least 16 points.
2NT	Balanced, 18-19 points. Invites partner to bid 3NT.

2	May be as short as three clubs, e.g. 5-3-2-3 shape.
2	May be as short as three diamonds, e.g. 5-3-3-2 shape.
2	Shows at least four hearts and 11-15 points. Insufficient strength to jump-rebid 3.
2	Shows six spades, may have a four-card side suit.
2NT	Balanced, 18-19 points. Invites partner to bid 3NT.

Pass	At least four clubs (typically five), 6-10 points. Correcting to partner's major with doubleton support is preferable.
Any new suit	A new suit at the 2-level shows at least five cards, and poor support for partner's major. Non-forcing.
2-major	Signoff in partner's major, shows 2-card support or a very bad hand with 3-card support.
2NT	Balanced, 11-12 points. Invites partner to bid 3NT.
3	At least four clubs, 11-12 points. Non-forcing.
3-major	A 3-card limit raise.

Pass	At least four diamonds (typically five), 6-10 points. Correcting to partner's major with doubleton support is preferable.
Any new suit	At least five cards at the 2-level, or six cards at the 3-level. Non-forcing.
2-major	Signoff in partner's major, shows 2-card support or a very bad hand with 3-card support.
2NT	Balanced, 11-12 points. Invites partner to bid 3NT.
3	At least four diamonds, 11-12 points. Non-forcing.
3-major	A 3-card limit raise.

Any new suit	At least six cards, and poor support for partner (a singleton or void). Non-forcing.
2NT	Balanced, 11-12 points. Invites partner to bid 3NT.
3-major	A raise shows 2-card support with 10-12 points or 3-card support with 10-11 points. Invites partner to bid game.
4-major	A 3-card limit raise, 11-12 points.

2NT	Balanced, showing 6-9 points. Non-forcing.
3/	At least six cards, non-forcing.
3	2-card support, or a very bad hand with 3-card support. Responder may have something as unsuitable as 2-2-5-4. Non-forcing.
3NT	10-12 points, balanced.

Any new suit	At least six cards. Note that this is less preferable to simply bidding 3NT.
3-major	A very bad hand with 3-card support. Non-forcing.
3NT	Signoff.

		Opener			Responder
		KT93			AJ5
		AKJ62			54
		J3			K985
		42			JT63
		Opener 1 2 (2) Pass			Responder 1NT (1) 2 (3)

		Opener			Responder
		AT9852			KJ
		AK5			842
		K42			AQ85
		4			J963
		Opener 1 2 (2) 4			Responder 1NT (1) 3 (3) Pass

		Opener			Responder
		QJT95			K2
		AK54			QJT3
		Q4			A853
		65			976
		Opener 1 2 (2) Pass			Responder 1NT (1) 3 (3)

		Opener			Responder
		K8653			6
		AK5			QJ6
		Q4			AJT532
		J65			972
		Opener 1 2 (2) Pass			Responder 1NT (1) 2 (3)

		Opener			Responder
		987			A62
		AQ873			K54
		AK4			Q763
		JT			K72
		Opener 1 2 (2) 4			Responder 1NT (1) 3 (3) Pass