1NT defence “Treat It As WEAK” Mod Cap, with OPTIONAL WOOLSEY (DISCUSS)
We use the same defence against a 2NT opening bid.
And a Gambling 3NT
And after our 1D (1NT)

X = Values, 15+ HCP
2C = Both Majors
2D = One Major (usually 6c suit)
2H = 5H, 4+m
2S = 5S, 4+m
2NT = Both minors
3C/3D = Natural, 10-14, constructive.
3H/3S = Natural, 10-14, constructive.
3NT = 4 level minor preempt

X of ALL third Seat NT is PEN.
X = ANY 5m, 4M.

Continuations after a Woolsey X
2C is PASS or correct to 2D
…… If partner corrects to 2D, then 2H is PASS or correct)
2D is Bid your Major (then 3M INV)
2H NATURAL
2S NATURAL
2NT ENQUIRY with 3C/D min 3H/S (C/D MAX)

x = 8-10 HCP, Any minor/Major 2 suiter.
Suits = natural

After a Double (Values/Penalty)
We are in a force up to 2H.
After a value showing double, the next double by either partner is for TAKEOUT. Further doubles are penalties.

After 2C (Both Majors)
(1NT) - 2C - (P) - ???
…… 2D = Pick a major
…… 2H/2S = To Play
…… 3H/3S = Constructive. Usually 4/5C support and mixed values.)
…… 2NT = Enquiry with same responses as 2H 2NT:
……….. 3C = Minimum hand (3D asks, natural responses)
……….. 3D = Longer Hearts
……….. 3H = Longer Spades
……….. 3S = 4/4.
……….. 3NT = 5/5
……….. 4C/4D = void in a 5/5?
…… 3C/3D = Natural, Forcing
…… 3NT = To play

In Competition - Maximal Running
After (1NT) - 2C - (X) - ???
………… Pass = To play in clubs
………… XX = Suggests equal major length
………… 2D/2H/2S = To play (not pass/correct)

After other bids:

Doubles by the 2C bidder show a shapely hand and suggest bidding on.
Doubles by responder are penalties.

After 2D (One Major)

(1NT) - 2D* - (P) - ???
………… 2H/2S = Pass or Correct. When correcting 2S to 3H opener can bid a new suit to suggest a good hand with that shortage.
………… 2NT = Enquiry with responses:
…………….. 3C/3D = Respective major, good hand.
………… …. 3H/3S = Natural, bad hand.
………… 3C/3D = Natural, Forcing
………… 3H/3S = Pass/Correct
………… 4H/4S = TO PLAY

In competition - Maximal Running
After (1NT) - 2D - (X) - ???
………… Pass = To play in diamonds
………… xx = Bid your majors
………… 2H/2S = To Play
………… 3M = Pass/Correct

If the opponents enter the auction, pass or correct is OFF.
Double suggests take-out and asks opener to bid their suit.
New suits are natural and N/F.

New suits are natural, non forcing.
ie. (1NT) - 2D - (2S) - ???
………… X = Pass/Correct.
………… 3C/3D/3H = Natural, NF.
………… 2NT = Strong Enquiry.

ie. (1NT) - 2D - (2NT) - ???
………… X = Good hand.
………… 3C/3D =
………… 3H/3S = Pass/Correct.

In general making the pass/correct bid is weaker than making the takeout double.

After 2M (Major & minor)

(1NT) - 2H* - (P) - ???
………… 2S = Natural, NF
………… 2NT = Enquiry with responses
………… ………… 3C/3D = Natural, Minimum
………… ………… 3H/3S = Respective minor, Maximum
………… 3C/3D = Pass or Correct. (When correcting 3D to 4C opener can bid a new suit to suggest a good hand with that shortage.)
………… 3S/4C/4D = Splinters in Hearts
………… 4H/4S = To play

In competition

After (1NT) - 2H - (X) - ???
………… Pass = To play
………… xx = Bid your minor
………… 2S/3C/3D = Nat to play
………… 2NT = Invite to game in hearts

After (1NT) - 2H - (2NT)* - ???
………… x = Good Hand, next X pen.
………… 3C/3D = Pass/correct.

(1NT) X is around 15+
Next X T/O

(1NT) P (2any) X is a good 13+
Next X T/O

Doubles of their NT responses
If they open a strong No-Trump, Doubles of their artificial bids are lead directing.
If they open a weak No-Trump. Our first double of their artificial bid shows values (15+). A subsequent double is for takeout.