Dear Ed and Peter,

The Declarer opens the bidding with a 'Weak Two Bid'. How do I as second player overcall this opening bid? - what are my options?

Thanks, John Smith

Reply Ed Hoogenkamp (South) and Peter van der Linden (North)

Dear John,

The options are basically the same as after an opening bid of one in a suit. Double is for take out, overcalls are natural and 2NT shows a balanced 16-18 (subsequent bidding is the same as over your 2NT opening).

Make one special agreement over the take-out double. Play a Lebensohl-like structure. This means you use 2NT as an artificial bid.

¹ Weak two

South can jump to game from something like 12 points. Without special agreements he would have to bid 3♣/♦/♥ on 0-11 HCP therefore. After all, South is under obligation to bid.
This 0-11 points range is too wide. Compare: over partner's double of an opening of one in a suit, responder makes an invitational jump bid with 8-11 points. If he would jump on an invitational hand as well after partner's double of a weak two opening, he would most often jump to the four level — too high if the doubler turns out to have a minimum. 

By way of the following Lebensohl-extension responder can distinguish between 0-7 and 8-11 hands.
- With 0-7 he bids 2NT, on which his partner is under obligation to bid 3♣ (unless he has 18⁺). Responder then either passes (if he has a club suit) or bids 3♦/♥ on which the doubler will usually pass.
- With 8-11 he bids 3♣/♦/♥ directly over the double.

There is more to tell about this Lebensohl-extension. What to do for instance if responder considers 3NT? How does he ask for a guard and how does he show one?
These schemes help:

Distinguishing hands with a spade suit and either a heart guard or not, doesn't seem necessary (after all, North doubles hearts so he will usually have spades) but comes in handy if North has an off-shape double (for instance 16 HCP or more with only three spades and no heart guard, or half a heart guard).

After a 2♠ opening there is less bidding space, so distinguishing between hands with a heart suit and either a spade guard or not, is not possible:

If you want to read still more about this convention, click here.

'Saludos desde Barcelona' and 'En hils fra Orkanger'

PS by Ed: Can't play this Lebensohl 2NT with Peter. Conflicts with our basic rule: when Peter bids NT it's never natural (he cannot become declarer in a notrump contract: impossible to reach a good score), when I bid NT it's always natural.

PPS by Peter: That's rubbish, Ed! 2NT isn't natural so (a) if I bid it, you might even become declarer in 3♣ and (b) if you bid it you will usually end up being declarer.
The real reason for us not to play it is the usual one: Ed cannot remember conventions if they turn up less than twice per session. And the conventions that do turn up that frequently still cost, since Ed statistically forgets them the first 4.17 times.