1NT Forcing (aka the Forcing Notrump) is a cornerstone of the 2/1 ("Two Over One") bidding system. After partner opens 1H/S, 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:

SQ52
H93
DA432
CJ987

     Balanced, 7 points. A 1NT response in any system.
SK98
HJ5
D532
CAK986

     With 11 points, this hand is too weak to respond 2C in the 2/1 bidding system.
S95
HA52
D54
CT97652

     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.
SK95
HA52
DK5
CJT987
     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 1H/S 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 1H : 1NT

2 May be as short as two clubs, e.g. 4-5-2-2 shape with insufficient strength to make a 2S 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.
2NTBalanced, 18-19 points. Invites partner to bid 3NT.

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

After 1S : 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 3H.
2 Shows six spades, may have a four-card side suit.
2NTBalanced, 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

PassAt 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-majorSignoff in partner's major, shows 2-card support or a very bad hand with 3-card support.
2NTBalanced, 11-12 points. Invites partner to bid 3NT.
3CAt least four clubs, 11-12 points. Non-forcing.
3-majorA 3-card limit raise.


After opener rebids 2

PassAt 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-majorSignoff in partner's major, shows 2-card support or a very bad hand with 3-card support.
2NTBalanced, 11-12 points. Invites partner to bid 3NT.
3DAt least four diamonds, 11-12 points. Non-forcing.
3-majorA 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.
2NTBalanced, 11-12 points. Invites partner to bid 3NT.
3-majorA raise shows 2-card support with 10-12 points or 3-card support with 10-11 points. Invites partner to bid game.
4-majorA 3-card limit raise, 11-12 points.


After opener reverses

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

2NTBalanced, showing 6-9 points. Non-forcing.
3C/D  At least six cards, non-forcing.
3H2-card support, or a very bad hand with 3-card support. Responder may have something as unsuitable as 2-2-5-4. Non-forcing.
3NT10-12 points, balanced.


After opener rebids 2NT

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


In Competition

If the opening 1H/S 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

OpenerResponder
KT93SAJ5
HAKJ6254
DJ3K985
C42JT63

Opener
1H
2 (2)
Pass

Responder
1NT (1)
2 (3)

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


OpenerResponder
AT9852SKJ
HAK5842
DK42AQ85
C4J963

Opener
1S
2 (2)
4

Responder
1NT (1)
3 (3)
Pass
  1. 1NT Forcing
  2. Natural, 11-15 points and at least six spades
  3. Inviting game with doubleton support and a maximum


OpenerResponder
QJT95SK2
HAK54QJT3
DQ4A853
C65976

Opener
1S
2 (2)
Pass

Responder
1NT (1)
3 (3)

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


OpenerResponder
K8653S6
HAK5QJ6
DQ4AJT532
CJ65972

Opener
1S
2 (2)
Pass

Responder
1NT (1)
2 (3)

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


OpenerResponder
987SA62
HAQ873K54
DAK4Q763
CJTK72

Opener
1H
2 (2)
4H

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

See also

  • Jacoby 2NT
    A 2NT response to 1H/S showing game-forcing support.

  • Limit Raises
    A major suit jump raise that shows game-invitational values and 4-card support.

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