Major Raises

Jacoby 2NT

A 2NT response to 1♥ or 1♠ is game-forcing with 4+ card support, asking opener to describe shortness and extra length.

What Is Jacoby 2NT?

Origin and Purpose

Jacoby 2NT was developed by Oswald Jacoby, one of the great bridge theorists of the 20th century (who also gave us Jacoby Transfers — a completely separate convention). The 2NT response to a 1♥ or 1♠ opening transforms an otherwise natural notrump response into a powerful game-forcing inquiry: "I have 4+ card support and 13+ HCP — tell me about your hand type." Before Jacoby 2NT, a responder with a game-forcing raise had few tools beyond a straight raise to 4♥ or 4♠, which immediately ended the auction and blocked any slam exploration. Jacoby 2NT keeps the auction alive and gives opener the opportunity to describe the hand's most salient features.

What Opener's Rebids Communicate

After 2NT, opener has a structured set of rebids. New suits at the 3-level show extra length — a good 5+ card side suit, indicating that the opener's hand has extra trick potential in that suit. New suits at the 4-level show shortness — a singleton or void in that suit. This distinction is crucial: 3-level bids say "I have stuff here — work with it," while 4-level bids say "I have nothing here — ruff things." The remaining rebids are 3NT (minimum, balanced, no special feature) and 4 of the opening suit (also minimum and flat, but even more emphatic about having nothing special). A rebid of 3 of the opening suit shows a very good trump suit — typically 6+ cards or a powerful 5-card holding with extra values.

Using the Information

Once opener has described the hand, responder becomes the captain. If opener shows a singleton in a suit where responder holds three worthless cards (e.g., ♦xxx opposite a singleton diamond), the duplicated values mean slam is unlikely. If opener shows a singleton in a suit where responder has aces and kings, those honors are all pointing the right way and slam is promising. If opener shows a minimum balanced hand, responder will usually settle for game. If opener shows a strong secondary suit, that suit can provide tricks for a slam. Responder uses 4NT (RKCB) to count keycards once slam seems viable, or signs off in 4 of the major if game is the limit.

Important Distinctions

Jacoby 2NT is strictly a non-passed-hand, uncontested convention. It requires 4+ card support and game-forcing values. Opener must not have bypassed the convention — if you open 1♠ and partner bids 2NT, that is Jacoby even with a balanced minimum. Jacoby 2NT also differs from a splinter bid: a splinter shows the shortness in the responder's hand, while Jacoby 2NT asks about shortness in the opener's hand. The two conventions are complementary — responder chooses between them based on whether their own hand has a singleton (splinter) or whether they want opener's hand described (Jacoby 2NT).

Core Rules

Trigger: When Jacoby 2NT Applies

After 1♥ or 1♠ opening — non-passed hand, uncontested. Responder holds 4+ card support and 13+ HCP (game-forcing values). Some partnerships require 5-card support; confirm with partner.

Alert required: The 2NT response to 1♥ or 1♠ is conventional — it must be alerted. Announce "Jacoby 2NT — game-forcing raise with 4+ card support" to opponents. All of opener's conventional responses must also be alerted.

Opener's Complete Rebid Schedule After 2NT

Opener's Rebid	Meaning	Implication
3♣ / 3♦ / 3♥ or 3♠ (new suit, below game)	5+ card SIDE SUIT — extra length, strong values in that suit	Responder evaluates if this suit provides extra tricks for slam
4♣ / 4♦ / 4♥ or 4♠ (new suit at 4-level)	SINGLETON OR VOID in that suit	Responder checks: are my cards in this suit useful or wasted?
3 of the opening suit	Extra-good trump suit — 6+ cards or powerful 5-card holding	Solid trump fit; may explore slam if values justify
3NT	Minimum balanced opening (12–14 HCP), no shortness, no second suit	Responder usually signs off in 4 of the major
4 of the opening suit	Minimum, flat — nothing special. "I have no extras, just bid game."	Slam is very unlikely; responder passes

Critical distinction — 3-level vs. 4-level new suits: A new suit at the 3-level shows extra LENGTH (a good 5+ card secondary suit). A new suit at the 4-level shows SHORTNESS (a singleton or void). This is the opposite of what some players expect intuitively, and it is the most commonly confused aspect of Jacoby 2NT.

After Opener's Rebid — Responder's Options

Responder's Follow-Up	Meaning
4 of the major	Sign off — game is the limit based on opener's description
Control bid (cue bid)	Slam try — showing a first-round control (ace or void) in the bid suit
4NT	RKCB (Roman Keycard Blackwood) — counting aces and trump king for slam
5NT	Grand slam force — asks opener to bid 7 with two of the top three trump honors

Slam Evaluation After Shortness Shown

When opener shows a singleton or void (4-level new suit), responder must evaluate the quality of their cards in that suit:

Wasted values: If responder holds KQx or AK in opener's singleton/void suit, those honors face a short holding and provide little extra trick value. Sign off in game.
Useful values: If responder holds low cards in opener's singleton/void suit (e.g., 432), there is no wastage and slam prospects improve — the short suit will provide ruffs or the suit can be discarded.

Shortness evaluation rule: Ask yourself: "Are my honors in opener's short suit pointing toward or away from the slam?" AK opposite a void = wasted. Small cards opposite a void = useful (ruffs available). QJx opposite singleton = questionable. Adjust your slam ambition accordingly.

Decision Tree

Two trees: the first for responder deciding whether to use Jacoby 2NT, the second for responding to opener's rebid. Click each node to expand.

Tree 1: Should Responder Bid Jacoby 2NT?

After partner opens 1♠ — non-passed, uncontested:

Do I have 4+ card spade support? ▶

No 4-card support → Jacoby 2NT does not apply. Respond naturally (1NT, 2♥, 2♣, etc.).

Do I have 13+ HCP (game-forcing values)? ▶

Do I have a singleton or void in a side suit? ▶

Consider a Splinter instead of Jacoby 2NT. A splinter shows YOUR shortness; Jacoby 2NT asks about OPENER'S shortness. If you want to describe your hand type, splinter. If you want opener to describe their hand, bid Jacoby 2NT.

Balanced hand (4+ spades, 13–15 HCP, no shortness)? ▶

Bid 2NT (Jacoby). After opener's description, sign off in 4♠ if opener shows minimum, or explore slam if opener shows extras.

Strong hand (4+ spades, 16+ HCP) with slam interest? ▶

Bid 2NT (Jacoby). After opener's rebid, proceed with 4NT (RKCB) or control bids based on the information received.

I have 4+ spades but only 10–12 HCP (limit raise territory)? ▶

Do NOT bid Jacoby 2NT — it promises game-forcing values (13+ HCP). Consider Bergen 3♦ (limit raise with 4-card support) or a standard 3♥/3♠ limit raise.

Tree 2: Responder's Decision After Opener's Rebid

After 1♠ – 2NT – ? — you are responder evaluating opener's rebid:

Opener bids 4♣ (singleton/void in clubs) — I hold ♣KQ7 ▶

Sign off in 4♠. Your ♣KQ are wasted — they face opener's shortness and add no extra tricks. Slam is unlikely despite your honor count.

Opener bids 4♦ (singleton/void in diamonds) — I hold ♦5 4 2 ▶

Explore slam — you have no wasted values in diamonds. Opener can ruff diamonds or discard them; your low cards are ideal opposite shortness. Use 4NT (RKCB) if values justify.

Opener bids 3NT (minimum balanced) — I have 14 HCP ▶

Sign off in 4♠. Combined 26–27 HCP with a balanced minimum; slam requires approximately 33 HCP in balanced hands. 4♠ is the right spot.

Opener bids 3♦ (5+ card diamond side suit) — I have ♦A K 4 ▶

Slam prospects are excellent — your ♦AK is perfect opposite opener's long suit. Use 4NT (RKCB) or make a control bid to investigate slam.

Opener bids 4♠ (minimum flat — pass me) — I have 16 HCP ▶

Pass. Opener has explicitly announced no extras and no special features. Even with 16 HCP, combined 28–29 HCP may not produce slam without a source of tricks or shortness to complement it.

Quiz

Ten questions in three levels. Click an option to reveal the answer and explanation.

Level 1 (Q1–Q4): Foundations · Level 2 (Q5–Q7): Intermediate · Level 3 (Q8–Q10): Advanced

Q1. You open 1♥. Partner responds 2NT (Jacoby). You hold:

♠ 3 ♥ A K J 8 7 6 ♦ K Q 4 ♣ A J 5
19 HCP — singleton spade, 6-card heart suit

What is your Jacoby 2NT rebid?

Correct: 4♠ — showing singleton or void in spades. The key principle of Jacoby 2NT is that new suits at the 4-level show shortness (singleton or void). You have a singleton ♠3, which is the most important feature of your hand. Bidding 4♠ tells partner: "I have a singleton or void in spades." With 19 HCP, you are clearly not minimum — this is a feature worth showing, not a minimum rebid. Partner can now evaluate whether their spade holding is wasted (e.g., ♠KQ74) or useful (e.g., ♠762) opposite your singleton.

Q2. You open 1♠. Partner responds 2NT (Jacoby). You hold:

♠ A J 8 7 6 ♥ K J 4 ♦ Q 6 5 ♣ A 4
13 HCP — balanced, no special feature

What is your Jacoby 2NT rebid?

Correct: 3NT — minimum balanced. With 13 HCP and a balanced 5-3-3-2 shape, you have a minimum but honest opening bid. No shortness, no good secondary suit. The 3NT rebid says "I'm minimum, balanced, and have no special features." This is different from 4♠ (even more minimum/flat) — 3NT is the precise description for a minimum balanced hand. Responder will usually bid 4♠ to sign off. Note that 3NT here is NOT offering to play notrump — it's a descriptive rebid.

Q3. After 1♠ – 2NT – 4♦ (opener shows singleton/void in diamonds), you (responder) hold:

♠ K Q 5 4 ♥ A K 4 ♦ K Q J 3 ♣ 8 7
16 HCP — strong hand with diamond honors

What do you bid?

Correct: 4♠ — sign off. This is the classic Jacoby 2NT wasted-values situation. Opener has shown a singleton or void in diamonds. Your ♦KQJ3 — three honors totaling 7 HCP — are pointing directly at opener's short suit. Against a diamond lead or diamond ruff, those honors provide virtually no extra trick value. Slam requires around 33 HCP in balanced settings; with wasted diamond values, your hand is effectively 9 real HCP rather than 16. Sign off in 4♠. This is exactly why Jacoby 2NT is so valuable — it prevents overreaching on "high card" slam tries that are actually duplication of values.

Q4. In Jacoby 2NT, what is the key difference between a 3-level new suit rebid and a 4-level new suit rebid by opener?

Correct: 3-level = extra length, 4-level = shortness. This is the most important rule in Jacoby 2NT to commit to memory. After 1♠ – 2NT, a rebid of 3♦ shows a 5+ card diamond side suit (extra length — more tricks). A rebid of 4♦ shows a singleton or void in diamonds (shortness — useful for ruffs). The logic is mnemonic: if you're showing a good, long suit, you can afford to bid it at the cheaper 3-level. If you're showing a short suit, you accept the higher 4-level to convey the different meaning.

Level 2 — Intermediate

Q5. You open 1♠. Partner responds 2NT (Jacoby). You hold:

♠ A J 8 7 6 ♥ — ♦ K Q 5 4 ♣ A J 7 6
16 HCP — void in hearts

What is your rebid?

Correct: 4♥ — shortness at the 4-level applies to voids too. The rule is simple: 4-level new suit = shortness (singleton or void). A void is actually better than a singleton — it eliminates all losers in that suit if responder can ruff. Bidding 3♥ would be a serious error: it promises 5+ heart cards and genuine heart length. Your 4♥ tells partner you have no hearts at all; they can now evaluate whether their heart holdings (e.g. ♥AK43) are "wasted" (opposite your void, the A and K are still tricks) or if they should explore a heart ruff situation in a slam.

Q6. After 1♥ – 2NT – 3♦ (opener shows a 5-card diamond side suit), you (responder) hold:

♠ A 5 ♥ K J 6 5 ♦ K Q 4 ♣ J 8 7 6
13 HCP — honours in opener's second suit

How should you evaluate your diamond holding?

Correct: your ♦KQ4 is a massive asset. This is the flip side of the "wasted values" lesson. When opener shows a 5-card side suit at the 3-level, high cards in that suit are the most valuable cards you can hold. Your ♦KQ4 means the combined diamond holding is likely AKQxx or better — a solid source of discards. This should tip you toward a slam try. Compare: if opener instead showed 4♦ (shortness), those same ♦KQ4 would be nearly worthless. The Jacoby 2NT machinery lets you accurately assess whether your honours are pulling their weight.

Q7. After 1♠ – 2NT – 4♣ (opener shows singleton/void in clubs), you (responder) hold:

♠ K Q 6 4 ♥ A K 4 ♦ A J 7 6 ♣ 5 4
16 HCP — no club wastage

What is your next bid?

Correct: 4♦ cue-bid. You have 16 HCP with zero wasted values in clubs (your ♣54 are worthless anyway, so opener's shortness costs you nothing). This is a prime slam hand. Before launching RKCB (4NT), show the ♦A via a cue-bid at 4♦ — this tells partner you have a diamond control and are interested in slam without committing to a specific level yet. Opener can now cue-bid 4♥ (♥A or void) and you continue to 4NT (RKCB). Jumping straight to 6♠ without checking keycards is too risky — what if opener is missing two aces?

Level 3 — Advanced

Q8. After 1♠ – 2NT – 3NT (opener shows minimum balanced), responder bids 4NT. What does 4NT mean here?

Correct: RKCB with spades as trumps. The moment responder bid 2NT (Jacoby), spades became the agreed trump suit. Every subsequent bid is in the context of spades as trumps. So 4NT by responder is RKCB (1430), asking for spades keycards. It is NOT quantitative. Quantitative 4NT only applies in notrump auctions where no suit has been agreed (e.g. directly over 1NT or 2NT openings). The 3NT rebid by opener was purely descriptive — it did not "set" notrump as the denomination.

Q9. You hold ♠4 ♥KQ76 ♦AJ54 ♣KQ65 (14 HCP, singleton ♠). Partner opens 1♥. Should you bid Jacoby 2NT or a splinter?

Correct: 3♠ splinter. Jacoby 2NT asks opener to describe their hand. A splinter shows YOUR hand. When you already know you have a singleton, there is no need to ask — you can tell. Bidding 3♠ immediately conveys: game-forcing values, 4+ hearts, singleton spade. Opener can now evaluate whether their spade holding is wasted (♠KQx = bad) or useful (♠xx = great). Use Jacoby 2NT when you want opener to reveal features you don't yet know; use a splinter when you have a specific short suit to show. The two conventions are complementary — Jacoby asks, splinters tell.

Q10. After 1♠ – 2NT – 3♥ (opener shows a 5-card heart side suit), you (responder) hold:

♠ A J 5 4 ♥ K 6 5 ♦ K Q 4 ♣ J 5 4
13 HCP — three-card heart fit with opener's second suit

Which assessment is correct?

Correct: make a slam try. A 3-level new suit rebid in Jacoby 2NT shows EXTRA LENGTH, not a minimum. Opener has a strong enough hand to show a second suit — this is a good hand. More importantly, your ♥K65 is now the most valuable card in your hand. Opener's 5-card heart suit combined with your ♥K65 creates a source of 3–4 heart tricks for discards in a spade slam. This is the exact opposite of a wasted-values situation. Bid 4♥ as a cue-bid (showing heart control and slam interest) or go directly to 4NT (RKCB). Simply signing off in 4♠ here throws away a likely small slam.

Hand Examples

Example 1: Jacoby 2NT Finds the Right Slam — Opener Shows Shortness

The auction: 1♠ – (P) – 2NT – (P) – 4♥* – (P) – 4NT – (P) – 5♦ – (P) – 6♠ – All Pass

*4♥ = singleton or void in hearts (4-level new suit = shortness).

NORTH (Opener)

♠ A K J 9 7

♥ 3

♦ A Q 7 5

♣ K J 4

17 HCP — singleton heart, strong hand, rebids 4♥

SOUTH (Responder)

♠ Q 6 4 2

♥ A K 8 6

♦ K 4 3

♣ A 7

15 HCP — 4-card spade support, uses Jacoby 2NT

EAST

♠ 5 3

♥ Q J 10 7 5

♦ 9 8 2

♣ Q 5 3

7 HCP — passes throughout

WEST

♠ 10 8

♥ 9 4 2

♦ J 10 6

♣ 10 9 8 6 2

1 HCP — passes throughout

Auction explained: South holds 15 HCP and 4-card spade support — a classic Jacoby 2NT hand. North rebids 4♥, showing a singleton or void in hearts. South evaluates: ♥AK86 opposite a singleton heart? These honors are pointing away from the void — but wait. South's ♥AK are actually very useful here: in a spade slam, the ♥AK will take tricks on their own. The singleton in opener's hand means hearts won't be led against the slam on the first trick, and South's heart winners provide extra tricks. South uses 4NT (RKCB). North's 5♦ shows 2 keycards (♠A and ♦A). With all those key controls and 32 HCP combined, South bids 6♠. The slam is cold.

Example 2: Jacoby 2NT Stops in Game — Opener Shows Minimum Balanced

The auction: 1♥ – (P) – 2NT – (P) – 3NT* – (P) – 4♥ – All Pass

*3NT = minimum balanced (no shortness, no extra suit). Not an offer to play 3NT.

NORTH (Opener)

♠ K J 4

♥ A Q 8 7 5

♦ Q 6 4

♣ J 9

12 HCP — minimum, balanced, no special feature → 3NT

SOUTH (Responder)

♠ A 5 3

♥ K J 9 4

♦ A K 3

♣ Q 7 5

15 HCP — 4-card heart support → Jacoby 2NT

EAST

♠ Q 9 8 7 6

♥ 6 3

♦ 10 9 8

♣ A 8 4

8 HCP — passes throughout

WEST

♠ 10 2

♥ 10 2

♦ J 7 5 2

♣ K 10 6 3 2

5 HCP — passes throughout

Auction explained: South has 15 HCP and 4 hearts — Jacoby 2NT. North holds a minimum 12 HCP with 5-3-3-2 shape and no shortness. The correct rebid is 3NT (minimum balanced). South reads this as "opener has no extras" and signs off in 4♥. Combined 27 HCP is just enough for game but not slam. 4♥ makes on normal card layout. Without Jacoby 2NT, South might have launched a cue-bid sequence on a misunderstanding about opener's strength, and ended up in a failing 6♥.

Common Partnership Misunderstandings

1. "Partner's 3NT Rebid Means We're Playing in 3NT"

After 1♠ – 2NT – 3NT, a player thinks the partnership has agreed to play 3NT as the final contract. They pass, leaving opener to struggle in 3NT with only a 5-2 spade fit. But opener's 3NT is a descriptive rebid — "I have a minimum, balanced opening with no special features" — not an offer to play notrump. The major-suit game-force is still in effect.

Fix: Internalize the rule: after Jacoby 2NT, opener's 3NT rebid is purely descriptive. It describes a minimum balanced hand. Responder must continue to 4♥/4♠ at minimum, or make a slam try. The only time you play in 3NT after Jacoby 2NT is if you make a deliberate independent decision to do so — which is essentially never.

2. "I Used Jacoby 2NT With Only 3-Card Support"

A player holds 14 HCP and three spades (♠AQ4) and bids 2NT over partner's 1♠. Opener, assuming a 9-card spade fit, evaluates accordingly and explores slam aggressively. But with only 8 combined trumps, contracts that depend on trump control prove fragile. Opener is making decisions based on a false premise.

Fix: Jacoby 2NT requires a minimum of 4-card support. This is non-negotiable. With 3-card support and game-forcing values, use other game-forcing bids (a forcing new suit response, then a jump or 4th-suit force). Some partnerships play 5-card support as the requirement — confirm with partner. But 3-card support is never acceptable for Jacoby 2NT.

3. "The 4-Level Bid by Opener Shows Length, Not Shortness"

After 1♠ – 2NT – 4♣, a player thinks opener has a good club suit. They count their ♣AK as extra value and launch into a slam try. But opener's 4♣ shows a singleton or void in clubs — the responder's club honors are completely wasted. The slam fails because the ♣AK face opener's short suit and provide no extra tricks.

Fix: Drill the core rule repeatedly: 3-level new suit = extra LENGTH; 4-level new suit = SHORTNESS. It helps to remember: "Going to the 4-level is a sacrifice — you're sacrificing bidding space to show a shortness that's important to know. The 3-level is cheap enough for showing a good suit." This is the single most common confusion in Jacoby 2NT auctions.

Practice Sequences

6 complete sequences covering the key Jacoby 2NT scenarios.

Sequence 1 — Singleton Shown → Slam Bid on Good Fit

West	North	East	South
	1♠	P	2NT*
P	4♦**	P	4NT
P	5♣	P	6♠
P	P
Jacoby. *Singleton/void diamonds (4-level). South has low diamonds — no wasted values — uses RKCB. 5♣ = 0 or 3 keycards. Slam bid.

Sequence 2 — Minimum Balanced → Sign Off in Game

West	North	East	South
	1♥	P	2NT*
P	3NT**	P	4♥
P	P
Jacoby. *Minimum balanced (3NT is descriptive, not a playing contract). South signs off in 4♥. All pass.

Sequence 3 — 5-Card Side Suit Shown → Slam Exploration

West	North	East	South
	1♠	P	2NT*
P	3♦**	P	4NT
P	5♥	P	6♠
P	P
Jacoby. *5+ card diamond side suit (3-level = length). South has ♦AK — perfect opposite opener's long suit. RKCB → 5♥ = 2 keycards → 6♠.

Sequence 4 — Void Shown → Wasted Values → Sign Off

West	North	East	South
	1♥	P	2NT*
P	4♣**	P	4♥
P	P
Jacoby. *Singleton/void clubs (4-level). South holds ♣KQJ — wasted values facing the shortness. Signs off in 4♥. Smart decision.

Sequence 5 — RKCB After Jacoby → Grand Slam

West	North	East	South
	1♠	P	2NT*
P	3♠**	P	4NT
P	5♦	P	5NT
P	7♠	P	P
Jacoby. *Solid/semi-solid trump suit (3♠ = excellent trumps). 4NT = RKCB, 5♦ = 1 keycard (♠K). 5NT = Grand Slam Force → North with AKQ in trumps bids 7♠.

Sequence 6 — Splinter vs. Jacoby Comparison

West	North	East	South
	1♠	P	4♦*
P	4NT**	P	5♥
P	6♠	P	P
Splinter — South has singleton/void in diamonds (shows SOUTH'S shortness, not NORTH'S). Compare Jacoby 2NT which asks OPENER to show shortness. *RKCB. 5♥ = 2 keycards → 6♠.

Expert Mistakes

Even experienced players make these errors with Jacoby 2NT. Recognizing the patterns avoids them.

Mistake 1: Confusing 3-Level Length vs. 4-Level Shortness in Opener's Rebids

This is the most common expert error. After 1♠ – 2NT, opener bids 4♦ intending to show a diamond side suit. But 4♦ = singleton/void, not length. Or conversely, opener bids 3♣ thinking it shows a club singleton, when 3♣ shows a 5+ card club suit. The entire slam evaluation by responder is based on the wrong premise — a wasted-values calculation becomes an add-values calculation, or vice versa.

Fix: Burn this into memory with a single clean rule: In Jacoby 2NT, new suits at the 3-level = length (good side suit); new suits at the 4-level = shortness (singleton or void). Before a session, recite it aloud: "3-level length, 4-level shortness." Write it in your system notes. Test each other on a few Jacoby 2NT hands at home until it's automatic.

Mistake 2: Jumping Directly to 4♥/4♠ Instead of Bidding Jacoby 2NT With a GF Raise

A responder holds ♠KQ74, ♥AK5, ♦Q43, ♣876 — 13 HCP with 4-card spade support. They jump to 4♠ immediately, "because we have enough for game." This blocks all slam exploration. If opener has ♠AJ985, ♥54, ♦AK5, ♣AQ3 (18 HCP), the partnership is cold for 6♠ but the premature 4♠ bid has ended the auction. The game jump should only be used for distributional, preemptive hands — not hands with genuine slam potential.

Fix: With 4+ card support and 13+ HCP, always use Jacoby 2NT (or a splinter if singleton/void). Jump to 4♥/4♠ should be reserved for weak, preemptive raises (like 5–9 HCP with good distribution) — not limit or game-forcing hands. Jacoby 2NT ensures slam opportunities are explored on every game-forcing raise.

Mistake 3: Treating Partner's Jacoby 2NT as the Natural 2NT Notrump Response

An opener who hasn't internalized Jacoby 2NT receives a 2NT response and treats it as showing a balanced 13–15 HCP hand (natural notrump). They rebid 3NT "to play" thinking responder wants notrump. The partnership lands in 3NT with an 8-card major fit sitting unseen, in a contract that may not be the best spot even if it makes.

Fix: After any 1♥ or 1♠ opening, a 2NT response (non-passed, uncontested) is Jacoby — an artificial game-force with 4+ card support. It is never natural notrump. There is no natural 2NT response in this position when playing Jacoby. Mark your convention card clearly and agree with every partner before play.

Convention Card

How to document Jacoby 2NT on your ACBL convention card, in the "Major Suit Raises" section.

MAJOR SUIT RAISES — JACOBY 2NT

Convention: Jacoby 2NT ✓ (2NT over 1♥/1♠ = game-forcing raise, artificial)

Applies when: Non-passed hand, uncontested, over 1♥ or 1♠ opening

Shows: 4+ card support (some pairs: 5+ card), 13+ HCP, game-forcing

3-level new suit = 5+ card SIDE SUIT (extra length, source of tricks)

4-level new suit = SINGLETON OR VOID in that suit (shortness)

3 of trump suit = Extra-good/solid trump suit — 6+ cards or powerful 5-card holding

3NT = Minimum balanced (12–14 HCP) — descriptive, NOT "to play in notrump"

4 of trump suit = Minimum flat — no extras, no shortness, no side suit

QUICK REFERENCE — OPENER'S JACOBY 2NT REBIDS

3♣ / 3♦ / 3♥ / 3♠ 5+ card side suit (LENGTH) — extra tricks available there

4♣ / 4♦ / 4♥ / 4♠ Singleton or void (SHORTNESS) — ruffing potential

3 of own major Solid/extra-good trumps (6+)

3NT Minimum balanced — no feature

4 of own major Minimum flat — nothing extra, sign off

Alert reminder: The 2NT Jacoby response must be alerted. Announce: "Jacoby 2NT — game-forcing raise with 4+ card support." All of opener's subsequent rebids (especially 3NT and 4-level suits) should also be alerted and explained to opponents on request.

Convention card summary text: "Jacoby 2NT: 1♥/1♠-2NT = 4+ support, GF (13+ HCP). Opener: 3-level suit = length (5+), 4-level suit = shortness (singleton/void), 3NT = min balanced, 3 of trump = solid/semi-solid, 4 of trump = min/flat."