Jacoby 2 No trump (Jacoby 2NT, Jacoby Two No trump)
After a major suit one level opening bid by partner, the conventional response of 2 No trump shows 4+ card trump support with an opening hand and interest in slam. After responder's 2 No trump call, opener's rebids to Jacoby 2 No trump are typically "slow-shows - fast denies" (strength)
Response Meaning after Jacoby 2 No trump (Jacoby Two No trump) 4 of Same Major Minimum hand
4 of New Suit A good 5 card side suits. Note: some play this as a void
3 No trump 14+ points and 5 in Major
3 of Same Major 14+ points and 6+ in Major
Splinter, indicating a singleton or void in the bid suit (most partners 3 of New Suit agree responder should have good trump honors or other extra values)
Notes:
Some partners play different ranges after Jacoby 2 No trump, such as:
4 of Same Suit Game sign off with 12-14 points and strength in bid suit 1. 3 No trump 14-16 points with a balanced hand
3 of Same Major 17+ points in bid suit
2. Some partnerships consider 3 trump sufficient when holding 2 strong honors
3. A minority play opener's 4 level new suit bid shows a void
When opponent (advancer) interferes after responder bids Jacoby 2 No trump:
Method 1: Basic
Response Meaning 1H - (P) - 2N - (3D); 4 of Same Major 4H 4H is signoff, no shortness
1H - (P) - 2N - (3D); Pass shows shortness in Pass P opponent's bid suit
1H - (P) - 2N - (3D); New Suit Shortness in bid suit 3S
1H - (P) - 2N - (3D); Medium or maximum hand, no 3 No trump 3N shortness
Method 2: Advanced (Mike Lawrence treatment), advancer interferes after Jacoby 2 No trump
Response Meaning
1H - (P) - 2N - (3D); 4 of Same Major 4H 4H is signoff
Pass is "waiting", with no controls and a good hand, or 1H - (P) - 2N - (3D); Pass control with a poor hand, or P strength and length in opponent's bid suit (hoping for Double)
1H - (P) - 2N - (3D); Double shows control (Ace or Double X King) in opponent bid suit
1H - (P) - 2N - (3D); 6+ trump and a control in 3 of Same Major 3H opponent's bid suit
1H - (P) - 2N - (3D); Singleton in opponent's bid suit 3 No trump 3N (or void if opponent bid 3S)
1H - (P) - 2N - (3D); Singleton in minor and a control 4 Minor 4C in opponent's bid suit
1H - (P) - 2N - (3D); Void in opponent's bid suit (or 3 Cue bid 4 in opponents' bid suit 4D No trump if opponent bid 3S)
When advancer interferes after responder bids Jacoby 2 No trump and opener has passed the bidding, showing various hand shapes (see above):
Response Meaning
1H - (P) - 2N - (3D); Double P - (P) - X Double for Penalty
1H - (P) - 2N - (3D); Ace in suit and 0-1 loser in 3 in new Major P - (P) - 3S opponent's bid suit
1H - (P) - 2N - (3D); 3 No trump King of opponent's bid suit P - (P) - 3N
1H - (P) - 2N - (3D); Ace in suit and 0-1 losers in 4 in Minor P - (P) - 4C opponent's bid suit