Opponent Intervenes

     

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

VIP Note: This does not apply to our 1 opening.: Please refer to 1 Opening for responses. The reason for this is that 1C may not be natural.

Please note: The following schema deviates from usual accepted continuations in ACOL - a 2-level or higher 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
- 2, 3.  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 with Hx!
                                                        2NT!: Trustcot: A sound raise to at least the 3 level
                                          4  SWISS. Balanced. Good raise to game, possible unspecified 2nd suit. This is not a splinter.
                                          4X: distributional game bid
With a minor 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 show a 5+ card major always!
                                                        Pre-emptive raises  to  345 levels     
                                          2NT!: A sound  raise to at least the 3-level
(as for a major opening also valid over a minor opening too)
Other responses:
1
1                              4+ cards. Treat as a 1 round Force. This bid can have a sizable HCP range 5-10+.+!..... permitted due to 1 round force. Denies an inverted minor raise unless Major is a 5 card suit. Use of this extended range breaks the redouble rule! Particularly useful with 2 suits to communiocate. 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, with guard, and
NO fit for opener. Opener encouraged to bid a 2nd suit or rebid his 6 card suit or  otherwise PASS
With 8+ HCP                    Redouble 8+HCP, any distribution & Technically promises a further bid. Denies sound raise for opener's suit; use direct raises or 2NT good raise to 3-level OR 4/ a good raise to 4 level.  Opener to respond to a redouble with his shortage (0-1)cards) if no further intervention, or NT's if balanced. If there is further intervention then double with shortage in opponents suit, rebid his 6+, bid a new suit shoing at least 5-4 or NT's with guard and no 2nd suit. Opener may jump in an unbid suit of 2-3 cards with at least 2 top honours AK or AQ
With < 8 HCP                 Bid a new 5 card suit, Non-forcing at 2-level
. or higher
                                                       Pre-emptive Jumps in 6+ card suits;  All non-forcing
PASS                                Nothing to say. Prefer this to showing a new suit if partner made a 3rd suit opening. Partner may re-open with a second suit (5-4 or better) OR a protective double (would confirm a normal 3rd hand opening).

Note:Redouble                  8+ HCP. Forcing. Suggests support in unbid suits  minimum of 3 cards - promises a further bid unless partner: PASS or makes a simple rebid of his suit. A redouble is mandatory with game values. If partners opening is light - he must rebid his opening 5+ card suit! Rebidding 1NT is 12-16 balanced (Crowhurst).

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

Also please refer to 1 for continuations.

E.G.
1-1-?
Responder must take into account opener's minimum  HCP count & 3rd hand openings!
Rubinsohl is not used over a simple overcall. (only over weak 2 jump overcalls made at the 2-level

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  345 levels;
                                        
2NT!: A sound raise to 3-level & 4+ card support - same as for Major opening!
Double                              (good7)8+ HCP, FORCING see
Negative Double. 15+ distributional hand with major fit need to start with a double. Partners rebid of 1NT is 12-16 with a balanced hand. 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 12-16 HCP Crowhurst, (2C inquiry shows 9+) it does not promise or deny a guard in 'Y'!
However if responder has passed  then 1NT rebid is 15-18 with Crowhurst ()2C inquiry 6+)

Opponents make a 2-level simple overcall

E.g 1-2, 1-2. ...?
a 2-level new suit  bid without jump shows <10HCP and a 5+ card suit.
a 3-level new suit bid is pre-emptive!
PASS                               Nothing to say or  possibly values lie in 'Y' - Partner should be prepared to 'PROTECT' if feasible.
*                                      (9)10+ at 2-levell
2 raise                           4-9 HCP Natural 3+ card support. Competitive. 1-2-2
2 raise                           4-9 HCP Natural 4+ card support. Competitive.  1-2-2 
  Following these simple Major raises, opener will usually PASS wih sub-opening values, may make a simple 3-level raise invitationally, bid game, bid a new suit - a trial bid -forcing to 3-level, cue-bid is also a trial bid. If RHO also bids then raises are competitive, new suits are trial bids.
3 & 3 raise                 5.-9 HCP pre-emptive with distributional values.
1-2-2                      10+ unlimited inverted minor raise. May hide a 4 card major.
1-2-34                 Competitive. 5: Distributional game bid - to play
2NT                                      Solid raise to 3X - Major or minor with 4+ card support
3NT                                      Natural. Good guard in 'Y'  No proper support for 'X' however usually 2 cards               
Swiss bids:                        Balanced, at least Game values, 4+ card Major support;  2(3) cards in opponents suit
New suit bids                  With or without a jump are distributional and <= 9 HCP - only exception are SWISS bids
Double                               Shows (9)10+ HCP unlimited & forcing
Direct Major raises         4-level distributional raise & 4+ card support
                                           3-level competitive Major raise - with 4(3 Spades only) card support
Cue-bid                            Shortage (0-1) in opponents suit with game values. Forcing. Probable 3+ card support for partner but could  be a strong 2-suited hand 5-5 or better in the remaining suits. Opener must rebid a second suit if present or failing that rebid with a moderate 6(5) card suit or bid 3NT with a strong guard in a flattish hand (5332 or 4333)

Note: 'competitive' means about 1 1/2  Trick short of a  'limit' raise made without the intervention

2NT NF rebid by opener following a negative double (9+) is 12-15(16), natural with a  Guard in 'Y'. Unbid minor is now an inquiry
3NT NF rebid following a negative double is Natural, with good 'Y' guard: To Play
2NT NF Natural following any new suit at 2-level is a denies support of responder's suit but promises good guard in 'Y'.

With a weak Jump overcall: 1X-J2Y(opp)-?

Show your fit                   This is the first duty! Direct raises are distributional limit bids
PASS                                 No fit. Possibly values in  'Y' - partner invited to make a protective double with good defensive values.
Double                             Opening values over 3-level intervention 11+. Probably interest in the other 2 suits. Can be converted to penalty
    "                                    9+ over 2-level jump overcalls - denies fit (see 2NT below). See 3Y below with shortage (0 or1 card)
    "                                   Mandatory with 16+ with exception of SWISS & 4NT agreeing partner's suit see below
3NT                                 Natural, Shows Game values, + a good guard in 'Y'. To play unless partner has other ideas!
Z  (new suit)                    Natural. 5 card at 2-level, 6 card at 3-level, 7+ cards at 4-level. Less than values for a Double
2NT                                 Good raise to 3-level in X - Major or minor opening
3Y                                    Cue-bid, game values: agrees partner's suit (Major or minor)
4CD                                SWISS bids - Over partner's Major opening, Balanced (but short in 'Y' permitted)
4NT                                 ERKCB, agrees partner's suit
3Y                                    Opening values, shortage in 'Y': 0-1 card -  5-5 or better in other 2-suits. No fit with 'X'

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  All distributions - invites partner to rebid a 2nd suit or rebid a 6+ card major or PASS for penalties
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 Major  2X At least minimum support:  3 card spades
or 4 card Hearts & 5-(9) HCP with a TOP honour!  a  limited    & competitive distributional bid
                                 34X At least 4 card support - requires good distributional values- competitive - use LTC.
Note: The issue with raising partner is the knowledge of trump controls with the 1NT bidder. These raises are safer only when holding at least a top trump honour.
Raise minor             2X: 10+, 4+ card support (inverted minor) - ignore holding a major suit
                                 34X distributional - competitive
2NT                         (9)10+ Rubinsohl - transfer to 3C, Shows 6 card club suit
                                 A continuation to Partner's suit shows 3 card support.
3                     Rubinsohl transfers to  3 Shows a 6+ card new suit and denies support for Partner, however if a transfer to partners suit it shows 4+ card support invitational. all other transfers denies any usuable support for 'X' .
3                           Transfer to 3NT (available - but this must be rare!)

Note: Transfers are preferred to put 1NT bidder on lead.

OR: INT 'unusual': 1X-1NT!(opp)-?

Usually showing a long minor or  interest in minors (alertable) or our own multi NT!

Single Raise of partner           Limit bids (not pre-emptive) shows 4 card support & likely to be  distributional
4                      SWISS Solid raise to 4, Balanced
Double                    (9)10+
leaves all options to partner - but denies fit
2 New suit               <9 HCP,   5+ card  suit         
2NT,3
          (9)10+ Rubinsohl transfers, Show a good (5)6 card new suit; transfer to partner's suit shows 4 card support
                               Rebids after ....2NT!-3C. Show a 5+ good card suit & a good control in lowest unbid minor.
3                         Transfer to 3NT

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

Raise partner           E.g. 1H - (2H or 2N or 3C) - 34H  shows limit raises to 34 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.

3-level Pre-empt e.g.  1S-3D(opps)-?

Raise partner - as above
Negative * - as above
New suit - as above
3NT                       Shows game values, A good guard, support for unbid suits.  Partner has  options :  PASS to play 3N; bid his 2nd suit; or game in his 1st suit
Note the imperative reason for this 3NT bid is the lack of bidding space when opponents pre-empt you to the 3-level. We have  ways to show game support: balanced: 4mi or unbalanced: either  new suit with control or directly bid game or Double then game see above sums this up) but there is no other good way to explore both the other major and a NT game. This is a  reminiscent of the sequence: 3mi-3NT...where one major is shown and looking to plat 3NT or game in the other major.

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

PASS: with nothing to say. Partner will protect if strong: 3-suited 3CD, 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

Overcalls of Strong 2Ma opening

PASS: with nothing to say
Raise: Competitively
Double: If normally able to make a 2NT with  invitational values - partner will show his distribution. See strong Major Two openings