2NT-3C-3S ("FOUR") OR 2D-3C-3S ("FIVE")

Pass after doubleShows a non-horrible four-card suit, willing to play in the doubled conventional bid if partner has trumps too.
RedoubleTo play, good five-card suit, but partner's allowed to take it out if unsuitable.
3NTto play, with a four-card major
4C, 4DMinorwood
4 of partner's majorto play
4 of the other majorBlackwood, agreeing partner's suit
4NTquantitative, inviting 6NT
5 of partner's majorquantitative, inviting a trump slam
5 of any other suitExclusion Blackwood
5NTquantitative, inviting 7NT
Any slamto play
Copyright 2015 Finn Clark.