A Crosswood bid in slam auctions is artificial, asking partner how many aces she holds. “Crosswood” is when you use clubs for diamonds and diamonds for club.

Examples:

W N E S

1♦ P 1♠

P 2♣ P 3♣

P 4♦*1P 4♠*2

P 6♣ P P

P

*1 Crosswood 0314, for ♣

*2 A=1/5 or 4/5

W N E S

P 1♣ P

2♣*1 P 2♦ P

4♦*2 P 4N*3 P

5N*4 P 6♦*5 P

7♣ P P P

*1 Inverted minors

*2 Crosswood 0314, for !C

*3 A=2/5 or 5/5, Q(C)=0

*4 King ask by 5NT

*5 K=1

♣ ♦ ♥ ♠