Comparison of Various No Trump Defenses

Overcaller's
Bid
Cappelletti DONT iDONT Brozel Lionel Landy
double penalty --> 2C
(relay)
--> 2C
(relay)
--> 2C
(relay)
4S + a
lower suit
(and 11+ hcp)
penalty
2C -->2D  (relay) C + a higher suit2 C + a higher suit2 C + H C + H
(11+)
majors5
2D majors D + a major suit2 D D + H D + H
(11+)
D
2H H + a minor1 majors H majors H H
2S S + a minor1 S (weak) S S + a minor1 S S
2NT minors   minors? minors minors minors

After the 2C relay (or 2D relay in the case of Cappelletti): 

Cappelletti, DONT and Brozel pass or correct to their six-card suit. 

iDONT: post-2C relay bids are the same as DONT immediate bids. (Click here for more detailed information on iDONT.)

Notes:

1Advancer bids 2NT to ask for overcaller's minor in Capp and Brozel.

2DONT and iDONT advancers may bid the next higher suit trying to find best fit.

3A strong DONT/iDONT advancer (14+) replies 2NT to ask about overcaller's strength. Modified Ogust bids are then used to specify strength and exactly which suits are held.

4Lionel Advancer with 10+ hcp may convert a Lionel double to penalty, raise spades (in several ways), bid 2C (or 2D with 4+ diamonds) asking overcaller to show her second suit, or bid a new suit.

5Landy advancer with equal majors bids 2D to the Landy 2C asking overcaller to “pick a major”.