Opponent Intervenes

Opponent Doubles: 1X(partner) - *(Opp) - ?

VIP Note: This document does not apply following our allerted 1♣! opening.: Please refer to 1♣ Opening for handling intervention. So 1X applies only to: 1♦, 1♥ or 1♠ openings made by your partner.

Please note: The following schema deviates from usual accepted continuations in ACOL - a 2-level  new suit bid is to be alerted as WEAK. Redouble and any 1 level suit bid are forcing.
Rubinsohl is not operative following any opponent intervention.

With a Major fit: Raise pre-emptively to 2|3|4 level, Spades  as  high probabilityof being a 5 card suit may be raised to the 2-level with Hxx that's 3 cards to a top honour. Exceptionally even Hx at the 2-level                          
                         With Hearts 4+ cards is required                              
                         2NT!: Trustcot style: A sound raise to at least the 3 level - this is NOT Baron (as used without intervention)
                         4♣|♦  SWISS. Balanced Sound raise to game, possible unspecified 2nd suit. This is not a splinter.
                                         
With a Diamond fit:             Single raise 10+, see Inverted Minors. Also Do Not show a 4 card major if you have one! The inverted minor raise does not deny a 4 card major! However  a 5+ card major must always be shown first! Partner must show a 4 card major over a  forcing minor raise as a 4-4 Major fit may still be available - but also necessary in exploring the hand e.g.                            1D-*(opp)-2D(10+ 4+ cards) - 2Ma(4 card)-...
                                          Pre-emptive D raises  to  3|4|5 levels     
                                          2NT!: A sound  raise to at least the 3-level (as for a major opening)
Redouble                           **   Potentially game going values 12+HCP balanced - not showing OR denying support for partner's suit. willing to play in 1Ma redoubled! puts pressure on opponents....
PASS:                               Natural, Limited support
Change of suit & fit:           1♥|1♠|2♦   Change of suit: 5+ cards. Treat as a 1 round Force. This bid can have a sizable HCP range (9)10++!..... permitted due to 1 round force.  Use of this extended range breaks the redouble rule! Particularly useful with 2|3 suits to communicate. A rebid of 1NT by opener is 12-16 balanced, with a 2♣ Crowhurst inquiry response with 9+ HCP.- just as if the opponent had not intervened.
With 8-10                         1NT!  Natural NF, and denies a 4 card fit for opener's suitr. Opener may rebid his 6 card suit or raise NTs otherwise PASS.

Important rebids by opener:

3♣  following a 1♦ or 1♠ opening:  Shows a 5-5+ hand <7LTC.
Opener rebids 1NT:                          Shows 12-16 balanced (Crowhurst).  Mandatory 2C rebid by responder when 9+

Opponents make a new suit overcall: 1X(partner)-1Y(opp)-?

Again please refer to our 1♣! openings for all continuations.


PASS                                Nothing to say OR good values in opponents suit. Partner (a good one!) will re-open with a protective double or a second suit
With a major fit                  Raise pre-emptively - 2, 3 or 4 level;  Over a 2-level response, trial bids operate.
                                         2NT!: A sound raise to 3-level; 4 card support required
                                         4♣|♦! see SWISS bids: Good raise to game with 4+ card, Balanced 15+
With  a 4+ card Ma'          At the 1-level a 4 card major must be bid with 4+ HCP. 1-level bids are to be treated as forcing.  A 1NT rebid by partner is 12-16 balanced. At the 2-level 5+ card suit 4-7 HCP is required & announced as non-forcing. A new suit by partner follows 5-4 rule
With a minor fit                  Single raise 10+, see Inverted minors   Pre-emptive minor raises  to  4|4|5 levels;
                                         2NT!: A sound raise to 3-level & 4+ card support - same as for Major opening!
Negative Double               (good7)8+ HCP, FORCING see Negative Double. 'asking about unbid suits'.With 15+ distributional hand and  fit need to start with a double - then show support on your rebid.. Partners rebid of 1NT is 12-16 with a balanced hand - see Crowhurst.. If opening light - a simple rebid must be made.
With <8 HCP                    Bid a new 5 card suit without jump (4 card major OK at 1-level); 
                                         Pre-emptive Jumps in 6+ card suits
With 8-10                         1NT, Natural, Balanced 8-10,  Denies good support for partner's suit,      
Cue-bid:                            Shows good holdings in both unbid suits, partner can bid a 3rd suit or bid a NT contract if partner guards 'X' well.
                                         3Y 2-suited. At least 5-4 in  the unbid suits
3NT                                  To play, Natural, Solid guard in 'Y' .

Note: A 1NT rebid by opener is structural. It shows a balanced 12-16 HCP (a Crowhurst 2♣ inquiry response shows 9+ - it does not promise or deny a guard in partner's suit 'Y'.

Opponents make a weak jump overcall 6+ card suit e.g. 1C!-2Y

* Shows interest in the remaining suits & 10+ HCP
Raising Partner opening are limit bids
Rubinsohl transfers show a 6+ card suit

PASS                              Natural
Double                             Negative in nature. Suggests the other 2 suits.
    "                                 
    "                                   Mandatory with 16+ with exception of SWISS & 4NT tacitly agreeing partner's suit see below
3NT                                 Natural, Shows Game values, + a good guard in 'Y'. To play unless partner has other ideas!
2NT                                Good raise to 3-level in X - Major or minor opening
4C|D                                SWISS bids - Over partner's Major opening, Balanced (but short in 'Y' permitted)
4NT                                 ERKCB, agrees partner's suit
3any new suit                    Length 7+ cards

With a 1NT strong overcall (Not unusual type): 1X-1NT(opp)-?

Usually 15+ balanced: Opponent is showing values and controls in your partner's suit
PASS                        A common bid in this sequence!
Double                     (9)+ HCP  suggests remaining 2 suits
Bid new suit              Not favoured! If an excellent 5 card suit with invitational values use Rubinsohl or Double
                                Can be used with a 7+ card suit weak.
Raise partner suit      Limit bids                    

With a 2-suited bid (Cue-bid, 2NT or 3♣ etc)

Raise partner           E.g. 1♥ - (2♥ or 2N or 3♣) - 3|4♥  shows limit raises to 3|4 level )
                               4♣|♦  SWISS balanced, Solid raise to game,  Slam potential (maybe short in opponents bid suit)
New suit                 Forcing. Any new suit. Agrees partners suit. Shows Control maybe 2-3 cards. Forcing to game. Partner may                                close in 3NT or 4 of his Major. Slam bidding will be TURBO. If partner cue-bids, bids 4NT or higher.
2-level Double         (9)10+   Negative Double. No fit. Usual potential support for unbid suit(s)
3-level  Double        (11)12+ Negative Double. No fit. Can be converted to penalties. Partner may also continue with an unbid suit.

Overcalls of 2♦ Multi e.g. 2♦-Y-? or 2♦-*

PASS: with nothing to say. Partner will protect if strong: 3-suited 3C|D, 2NT or a Protective double with a balanced hand. Also, if weak, competitively discloses a  good 6 card major 2S, 3Ma competitively.4
Double: shows a normal 2NT response. Partner develops his hand normally

Overcalls of 2♣ Opening

See 2♣.  conventional responses for all interventions

Overcalls of Strong 2Ma opening