Mini-Roman or Mini-Roman 2 Diamonds is contract bridge convention whereby the opening bid of 2 shows a three suited hand and 11-15 high card points (HCP). The convention is meant to help responder to judge, more quickly, the right level of the contract and the best trump suit (or if notrump would be better).
The Roman Club system, developed in the 1950s, included a treatment of these three suited hands with 2 showing a weaker hand and 2 a stronger hand. A response by partner of 2NT was forcing to game.[1]
The Blue Club system of bidding was developed and became widely popular in the 1960s and included a 2 bid to show a 4-4-4-1 hand with 17-24 HCP[2]
An opening bid of 2 shows one of two distributions: 4-4-4-1 or 5-4-4-0 (the five card suit is usually not a major suit) and 11-15 HCP
The Mini-Roman 2 opening is a forcing bid. Responder has the following options.
Opener's rebids:
The advantage to the system is the power of the short suit. The hand lends itself to a cross ruff.
A disadvantage is the loss of the 2 bid for other purposes including a weak 2, a Strong two or a Multi 2.
There is a wide range of variations available to this convention (usually subject to partnership agreement) and these include: