It came to my attention recently that there is a gap in the knowledge of many players pertaining to this auction: partner opens the bidding and RHO doubles. What are the standard responses?
Most experienced players play that a bid at the one-level over a takeout double is a one-round force, while a bid at the 2-level is non-forcing--with less than 10 HCP. In the box on the left side of the convention card entitled "OVER OPP'S T/O DOUBLE" it is customary to check the box "New Suit Forcing:: 1 level" and not to check the "2 level" box.
Let's say that partner opens 1♠ and the next hand doubles. What should I bid?
Without the intervening takeout double I would bid 2♥, game-forcing. As the bid of 2♥ is non-forcing over the double, however, I must find another call. The only forcing bid available is a redouble. I must start with a redouble and hope to be able to adequately describe my hand in future rounds of bidding. Had partner opened 1 of a minor, I could have responded 1♥ with this hand, forcing. Note that a jump shift over a takeout double is similarly non-forcing, so I can't jump to 3♥.
This hand would be suitable for a 2♥ bid after partner opened 1♠ and the next hand doubled:
Opener may raise with extra values and a fit, but otherwise pass.
See you at the table!