The Strong Two-Bid
If 2 ♦, 2 ♥, and 2 ♠ are weak bids, what if you're dealt a hand such as this?
♠ AKQ10643
As you learn more and more bridge language, you will understand that this hand is a “rock crusher.” It's the kind of hand you dream of if you're playing for money.
You don't want to start this one out with 2 ♠ or even 3 ♠, which is usually even weaker than a weak two-bid but with a longer suit. So if 2 ♠ isn't strong, what can you do?
The answer is that you open the bidding with 2 ♣ — that's your artificial catch-all bid for all your strong hands (except for 2NT, which is narrowly defined). An artificial bid is any bid that doesn't indicate anything about the particular suit named. In other words, when you open 2 ♣, it doesn't say anything about clubs — only that you have a very strong balanced hand or any other big hand with a long, strong suit.
A 2 ♣ bid is one that cannot be passed unless the player in the next seat takes some action (in this modern world of active bidders, you can count on it). Your plan as the 2 ♣ opener is to listen to your partner's response and describe your hand further.
Responding to 2 ♣
Your first responsibility as responder when your partner opens 2 ♣ is to describe your hand. In general, you won't have a lot of strength, but you might have a decent suit you can tell your partner about. Your most common response, however, is likely to be 2 ♦, a “negative” response — negative in the sense that you don't have a lot of help for your partner. Here are the responses to a 2 ♣ opener:
2 ♦ — a weak hand (0–5) or a hand without a good suit
2 ♥ — at least five hearts with at least two of the top three honors in hearts
2 ♠ — at least five spades with at least two of the top three honors in spades
2NT — a balanced hand with modest strength (usually 8–10 HCP) but no long suit
3 ♣ — at least five clubs with at least two of the top three honors in clubs
3 ♦ — at least five diamonds with at least two of the top three honors in diamonds
Note that the 2 ♦ bid does not necessarily indicate a poor hand. It says only that you don't have a five-card suit with two of the top three honors. The reason it's important to restrict these responses is that the 2 ♣ opener may have a fit for the responder's suit, but if the suit is of poor quality, such as Q7654, the opener will be poorly placed to decide on the final contract. If the opener knows it's a suit headed by honors, she will have a much better idea of how to proceed.
Say the opener holds:
♠ AK
That's a 2 ♣ opener for sure — 21 HCP, great diamond suit. If the responder bids 2 ♥, the opener will really be excited if their agreement is that 2 ♥ shows at least five hearts and two of the top three honors in the suit. The opener can easily envision game in hearts — and there might be a slam.
On the other hand, if 2 ♥ could be bid on Q7654, there might be three or four losers in that suit. That's why it's important to have these handy agreements in place. It's not too taxing on the memory, right? Five-card suit, two of the top three honors. Piece of cake.

