Multi (2♦)

I regard Multi vs Multi as a specialized version of Unusual vs Unusual. X remains “penalizing” either suit but longer. Cuebids are reordered and show unbid (minor) suits.

Different from BTU vs Unusual, 2♠ and 2NT are two-under transfers. The non-forcing Herbert negative step serves as an escape.

(2♦) X

Here I recommend a modified version of Rumpelsohl. Frequently pass 2♦x with 4+ diamonds to ease slam exploration, especially for minor suit slams.

When the right-hand opponent bids, X is penalty and usually short in the other major. We play Rubinsohl here because we need to bid diamonds. Please refrain from penalizing with length in both major suits. It is usually better to make our own contract than setting their doubled partscore.

After opener shows their major, doubler always penalizes when holding the same suit. This action is mostly safe because doubler sits behind the opener. More importantly, this treatment creates a negative inference that a pass implies holding the other major.

• (2♦) X (2♠) - (3♥) X = Usually hearts
• (2♦) X (2♠) - (3♥) - = Spades!

(2♦) 2♥

Partner is limited and balanced like the 1NT opening. I suggest playing like Rumpelsohl at 2♥x.

Transfer to minors