DONT can be used with low hand strength, but intervenor must have good suits when . DONT features the following calls: • Double – shows any single suit (six or more cards); advancer bids 2, after which intervenor corrects to his actual suitor or Passes if it is clubs. • 2, 2, 2 – shows the bid suit and any higher-ranking suit • 2 – shows spades (six or more cards) Preferences vary as to the use of the 2 bid. Some treat it as weaker than the sequence of a double followed by 2; others play it as showing a solid (runnable) spade suit; other treatments are possible and partnership discussion and agreement is necessary. DONT is normally applied as a defense to strong notrump opening bids, but some people have created various modifications to DONT to apply them to weaker notrump openings. The difference is that the bidder shows opening-bid values and the partner of the doubler may pass to convert the single-suited hand into a . Against the mini-notrump opening bid which shows 10-12/13 HCP (also known as the
Kamikaze 1NT): • Double is for penalty and shows 13+ points with any shape. • 2 shows any single suit; partner bids 2, after which the intervenor corrects to his actual suit. • 2, 2, 2 shows the bid suit and any higher-ranked suit, with
clubs as the highest-ranking suit.
Responses There are variations in the agreed responses, and partners should establish a clear agreement. One common system of responses is: •
Pass – Advancer is willing to play in the suit bid. Advancer will often have shortness in a higher-ranking suit or suits. •
Bid of the next cheapest suit (e.g. 1NT – 2 – Pass – 2) – Advancer asks overcaller to bid his other long suit, or pass if the bid is in that suit. Advancer will usually have at least 3-card length in all higher-ranking suits. If Advancer asks for overcaller's other suit and then rebids 2NT after overcaller shows it, advancer is making a strong game invitation in the second suit. • However over a 2 bid (1NT – 2 – Pass) a bid of 2 is simply a preference for the other known suit, and shows much the same strength as would a raise of the heart suit. Similarly a bid of 3 (1NT – 2 – Pass – 3) would tend to be preemptive. •
Bid of a new suit that is not the cheapest suit (1NT – 2 – Pass – 2 or 2) – Natural, showing advancer's own 6-card or strong 5-card suit. • '''A raise of overcaller's 2 or 2 overcall or rebid''' tends to be preemptive. • '''A raise of overcaller's major-suit overcall or rebid''' is mildly invitational. 2NT shows the strong invitation. • Others treat this as weak also, and insist that all invitational sequences go through 2NT. •
2NT – A strong game invitation that asks overcaller to bid the other long suit at the 3-level (or 4-level, if the second suit is a major and overcaller is strong enough to accept the invitation). Advancer promises excellent support for all higher-ranking suits. ==Over strong club opening bids==