OTHER OPENING BIDS
  HCP see Note Min length CONVENTIONAL MEANING SPECIAL RESPONSES Notes
1♣ 9+ ¨

3

   Splinters. 2NT natural

1.1

1.2
1♦ 9+ ¨ 4  
1♥ 9+ ¨ 4   Jacoby 2NT
1♠ 9+ ¨ 5  
3 bids 0+ ¨ 6 3NT = solid minor    
4 bids 0+ ¨ 7      

DEFENSIVE METHODS AFTER OPPONENTS OPEN
Opponents Open A Natural One of a Suit CONVENTIONAL MEANING SPECIAL RESPONSES Notes
Simple overcall Usually 5+ cards    
Jump overcall Pre-emptive; 3♣ = 2 highest unbid suits    
Cue bid Ghestem 2 extreme suits   1.3
1NT Direct 15-18 As 1NT  
Protective 11-14  
2NT Direct 2 lowest unbid suits, weak/strong   1.3
Protective 20-22 As opening 2NT  
Opponents Open With DEFENSIVE METHODS SPECIAL RESPONSES Notes
Strong 1♣ Truscott   1.4
Short 1♣/1♦ Treat as natural    
Weak and Strong 1NT Modified Landy; 2♣=both majors, 2♦=equal length 1.5
Weak 2 Dbl for take-out; 2NT=16-18 bal. Lebensohl 1.6
Weak 3 Dbl for take-out    
4 bids Dbl for take-out    
Multi 2♦ Dbl: 13-15 or 19+; 2NT=16-18 Lebensohl 1.6

SLAM CONVENTIONS
Name Meaning of Responses Action over interference
Roman Key Card Blackwood 5♣=1/4, 5♦=0/3, 5♥/♠=2/5 without/with trump queen. 5NT asks for lowest side-suit king Dbl=0/3, pass=1/4, etc
Minor-suit RKCB 4♣/♦ agrees/sets the bid suit as  the trump suit, and is RKCB. Either bid may be made in response to an opening 1NT/2NT.
 
COMPETITIVE AUCTIONS

Agreements after opening of one of a suit and overcall by opponents:

Level to which negative doubles apply

3♠

Special meaning of bids

2NT=natural, cue-bid=Jacoby

Exceptions/other agreements

After  opponent's UNT, lower-suit cue-bid is forcing raise, higher-suit is forcing with 4th suit

Agreements after opponents double for takeout
Redouble 10+ New suit Forcing Jump in new suit Fit-jump
Jump raise Pre-emptive 2NT Good raise Other  
Other agreements concerning doubles and redoubles:
Doubles are for take-out unless: we have a fit; we have pre-empted; we are doubling a naturally-bid NT.
After penalty double of 1NT, next double by either player is take-out.
 

OTHER CONVENTIONS
Fourth-suit forcing [1♠ is natural]
After 1X-2Y, 2NT is game-forcing [3♣ requests more information], 3NT = flat 15/16
Unassuming cue-bids (show good raise of partner's suit or very strong hand)
Directional asking bids
1NT rebid is 15-17 [2♣ is checkback], 2NT rebid is 18-19
 

SUPPLEMENTARY DETAILS [1]
(Please cross-reference where appropriate to the relevant part of the card and continue on back if needed)
1.1 Splinter jump shows support for partner [min 4] with typically singleton in bid suit. A splinter bid can be an immediate response, opener's rebid, or an unnecessary [to be forcing] bid at any stage of the auction.
1.2 Jacoby 2NT promises 4+ trump support and is forcing to game. Opener rebids 4-major if minimum. 3-new-suit as trial bid, 4-new-suit as splinter.
1.3 Ghestem or UNT shows min 5-5 in specified suits, either weak or strong [not intermediate]
1.4 1-level overcall or 2♣ shows that suit and next higher suit. Double shows suit doubled and non-adjacent suit, 1NT shows other two non-touching suits. Jump overcall is single-suited.
1.5 2♣=both majors, 2♦=4-card major plus longer minor, 2-major=minimum 5-card suit
1.6 If partner doubles a weak 2-bid, 2NT shows a weak hand [<8] and requests a 3♣ relay.