Unusual vs. Unusual is a competitive bidding convention used in contract bridge

Contract bridge

Contract bridge, usually known simply as bridge, is a trick-taking card game using a standard deck of 52 playing cards played by four players in two competing partnerships with partners sitting opposite each other around a small table...

 by the opening side after a defensive bidder has made an overcall showing two suits. When you or your partner has opened the bidding and an opponent has made an overcall which shows a two-suited hand (e. g., a Michaels Cue Bid

Michaels cuebid

The Michaels cuebid is a conventional bid used in the card game contract bridge. First devised by Mike Michaels of Miami Beach, it is an overcaller's cuebid in opponent's opening suit and is normally used to show a two-suited hand with at least five cards in each suit and eight or more points.After...

 or an Unusual notrump

Unusual notrump

In the card game of bridge, the unusual notrump is a conventional bid showing two lower unbid suits.When the right-hand opponent opens 1 or 1, the immediate overcall of 2 NT shows at least 5-5 in the minor suits and, presumably, a weakish hand...

 Overcall), one may defend against the defensive bidding with the following methods:

When the opponent’s two-suited overcall explicitly specifies two suits

• A bid in partner’s suit or a new nonadverse suit is competitive without showing game interest.
• A cuebid of the opponents’ lower ranking suit shows an invitational limit raise of partner’s suit with a likely 5-card side suit in the other nonadverse suit.
• A cuebid of the opponents’ higher ranking suit shows a game forcing raise with a likely 5-card side suit in the other nonadverse suit.
• A double shows the ability to penalize at least one of the opponent’s two specified suits.  Any subsequent double by the partnership is for penalty.

When the opponent’s two-suited overcall identifies one suit and leaves the other suit unspecified

• A bid in partner’s suit or a new nonadverse suit is competitive without showing game interest.
• A cuebid of the opponents’ known suit shows a raise of partner’s suit. The raise is invitational limit raise or stronger. The cue bid raise implies a 5-card side suit (probably, not the overcaller’s unspecified second suit).
• A double shows the ability to penalize at least one of the opponent’s implied suits. Any subsequent double by the partnership is for penalty.

Additional information

Typically, raises show either four-card or longer trump support or three-card support with a splinter in a known, adverse suit. Since the overcaller with the two-suited hand probably has a short holding in the opening side's trump suit, one expects the adversely held trumps to break unevenly. Thus, the opening side should have either nine or more trumps or good ruffing values in the hand with short trumps.

The Unusual Versus Unusual (or, unusual over unusual) convention has many variants. This article presents only one variant. Thus, an agreement to play "Unusual vs. Unusual" with a new partner should include a discussion of what each partner means by "Unusual vs. Unusual" concluding in a joint agreement for the partnership.