Four notrump (4NT) is a bid in bridge which specifies a contract for the partnership to take 10 tricks without a trump suit. It is a game contract in duplicate bridge.
As it scores the same as 3NT when made with the same number of tricks taken, but requires one more trick to make, it is always more desirable to play in 3NT compared to 4NT. Therefore, this bid is mainly used when there is a slam interest, and it is often conventional.
As an opening[]
The natural meaning of a 4NT opening is 28-30 HCP, balanced hand.
However, as these kind of hands are so rare, and when a 2♣ opening is strong and forcing, they can be bid by the sequence 2♣ - 2♦ - 4NT, therefore a number of conventional meanings are developed with this bid:
- to ask the number of aces
- to ask for a specific ace
- to show a freak hand with at least 6-5 in the minors
- To show a good long minor worth 5 of a minor itself.
As a response[]
A 4NT response to a suit opening is usually some form of Blackwood, asking the partner for aces.
A 4NT response to a notrump opening is usually natural, a quantitative invite to 6NT.
In later bidding[]
A non-jump 4NT in constructive bidding, when no suit has been agreed, can be natural.
If a suit has been agreed, 4NT is almost always some form of Blackwood, usually Roman key card Blackwood.
As an overcall[]
A 4NT overcall when the bidding is at the 4-level is normally unusual, specifying a freak hand with at least 6-5 in the unbid suits.
| Bids |
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1♣-1♦-1♥-1♠-1NT |