The takeout double with 13-17HCP
This double calls for the other 3 suits. Ideally you should have 4 cards in each suit and...be short in the opening suit!
- After a minor opening you need at least 7 cards between the two majors (4+3) and less than 4 cards in the opening suit.
- After a major opening you need 4 cards in the other major and to be short in the opening suit.