Used in various point count range such as 17-21, 20+ HCP
2 ( Maxi Roman } shows 4,4,4,1 or 5,4,4,0 distribution .
Because of high point count responder cannot pass 2 even with a bust hand.
Responders bids are 2/2/2NT
2NT asks opener for his shortness.
If responder bids 2/2 opener will raise the suit with a fit or bid 2NT which tells responder that he has just bid his shortness. It is up to responder to pick the game contract unless he has a completely bust hand in that case he bails at the 3 level.Any further action is up to opener.
Some like to play Mini Roman/Maxi Roman combination bid.The Maxi Roman point count is also partnership agreement but we have been experimenting with 20 or more HCP in conjunction with Mini Roman 11-15 with 4 spades.
When played this way the only disadvantage is responder cannot pass 2 .
2NT is still the asking bid.Opener need not jump at this time to show Maxi Roman hand because responder will never pass when Opener shows his shortness.If responder signs off below game Opener will bid game with the Maxi hand and pass with the Mini hand.If responder bids game and Opener has Maxi hand chances are the bidding will continue.In any event it will become clear to responder what his partner has.
What happens when responder bids 2/2 and opener has Maxi hand.
If responder bids 2/2 then opener will raise THE SUIT unless it is his shortness which in that case he bids 2NT. That tells responder that he has a Maxi hand and shortness in the bid suit.Knowing his partner has a Maxi hand it is up to responder to pick a game contract unless he has an absolutely bust hand in which case he bails at the 3 level. If he does not bid game any further action is up to opener.