A Weak Two bid is a mini pre-empt usually showing 6 - 10 High Card points and a six card suit. Depending on your bidding system you can play them in diamonds, hearts and spades (weak three twos) or just hearts and spades (Benji and Reverse Benji). There are two normal methods of responding to a weak two opening bid, OGUST and “Features” among others. Different people have different ideas about which is best but as always it’s normally best to play the one which you and your partner understand the best.. 

What does a weak two bid show?

A Weak Two Bid is a bid of 2♦ , 2♥ , or 2♠ that shows 6-10 HCP and exactly 6 cards in the bid suit. Not 5 or 7, but exactly 6. The bid is said to be pre-emptive. That is taking a lot of the bidding space away from the opponents. However, the bid is also meant to show your partner that you have some points and a good suit. 

Historically Weak Two bids were very disciplined. You only made them with 6-10 HCP and a six card suit and beyond that your suit should be fairly good: At least two of the top three honours (A,K,Q) or three of the top five (A,K,Q,J,T). In addition, you shouldn't have a four card major. Nowadays a lot of this discipline does not apply, more and more people are opening with very light hands in order to pre-empt the opponents more and more. You will often see weak two bids made on jack high suits and in some cases a 5 card suit. In third seat anything goes almost. It’s best to agree with your partner if you open a weak two with a four card major suit in addition to the weak two suit. Sometimes you will miss a major suit game by opening the weak two and other times it will work out well for you.

What if I have a 6 card suit with 11 HCP? 

Some people will open a weak two, others will pass, or open at the one level, your hand will meet the rule of twenty. (If the number of cards in your two longest suits plus you high card points is equal to or greater than 20 open the bidding at the one level).  

Responding to a weak two bid

If you don't have at least 2 card support, you should pass unless you have 16+ HCP. (See below)

If, however, you have few points but quite a few cards in the weak two suit, then you should raise the bid. The more you have the higher you should raise it. This depends on your vulnerability, but the guidelines are something like:

• With 3 card support: bid 3,
• With 4 card support: bid 4,
• With 5 card support: bid at least 4, maybe 5.

Any raise by responder is a signoff bid, and opener should not bid again. 

If your partner opens 2 of a major and you raise to four of the major, You might be pre-empting, with very few points and a long suit, or you might have a lot of points (possibly 20 or more). How does partner tell what you have? 

He can’t! He passes either way. A nice side benefit is that the opponent's might not be sure if you are stealing the hand from them or if the hand really does belong to you. And when opponents make mistakes at the 4 level or higher, you tend to get a lot of points.

With 16+ points you probably have game on but may need more information from your partner.

To obtain more information from partner you bid 2NT asking the weak two opener to describe their hand, the responses are the different depending on the system you play, OGUST or "Features"

OGUST Responses

3♣  Shows a weak suit with poor points

3♦  Shows a strong suit with poor points

3♥  Shows a weak suit with good points

3♠  Shows a strong suit and good points

3NT Shows that you have the Ace, King and Queen in the weak two suit

To respond showing a strong suit you must have two of the top three honours

To respond showing strong points you need a "good" 8, 9 or 10 points

Armed with this information the responder to the weak two opening will be able to place the final contract.

"Features" responses

There are many different ways of responding using features and the following is just one of many, they can be very complicated.

After 2NT the opener responds as follows:-

Say you open 2♥ 

3♣  Club Feature*, upper range Weak Two

3♦  Diamond feature*, upper range Weak Two

3♥ Lower range

3♠ Four-card suit (we may belong in 4♠) in an upper range hand.

3NT Two of the top three honours in the suit and an upper range hand

* A feature is typically an honour with some length, e.g. Qxx, Kxx, Ax.

More information on "features" response can be found in Andrew Robson's Weak Two Book

Final Notes

OGUST seems to have more defined responses than "Features" but as always it is better to play the system that you and your partner are most comfortable with.