Defending After Opponents Bid Unusual 2NT
 
If right-hand opponent overcalls partner's opening bid with an unusual 2NT, 
responder's initial decision will be driven by whether he wants to compete for 
the contract, investigate game, consider penalising opponents, just stay out of 
things.
Possible Actions
	- an immediate raise of partner's suit is competitive, with no aspirations 
	for going further. Partner needs to know the score before opponents get 
	together and take the level too high for us to get further involved.
- a direct bid of the fourth suit, usually the other major, shows a 5-card 
	suit [minimum] and is non-forcing. With a stronger hand responder would 
	cue-bid RHO's higher suit.
- cue-bidding 3♣ [assuming that's RHO's lower suit] promises 
	support for opener's suit, but forcing only to the three-level.
- cue-bidding 3♦ [RHO's 
	higher suit] promises 5+ cards in the other major.
- an immediate double shows general values [10+ HCP], with a preparedness to double at least 
	one of RHO's suits for penalties. Could be short in opener's suit, certainly 
	without obvious support, but could have a 3-card suit if the opening bid has 
	only promised a 4-card suit. A subsequent double after an initial pass would 
	be take-out.