Multi 2 Diamonds

Multi 2 ♦ : opening and responses
Multi 2 ♦ is offering some benefits during the bidding :

Most of the time, the contract is played by the strong hand , protecting tenaces and making the defenders' job more difficult.
it leaves space for 2 ♥ or 2 ♠
It is possible to look for a game but stop at level 3
it makes the defense difficult.. the opponents don't know what the opener's suit is!

3 types of hands for a multi 2 ♦ :

Weak 2 major openings
Super 2 NT with 22-23 HCP
strong minor one suiters

Dominique recommends to use it with weak 2 major opening hands !

S	W	N	E

Exercise E9475 According to the multi 2 ♦ convention, open 2 ♦.. a hand for which you would have opened a major weak 2

Responding to a multi 2 ♦
In the simple version, it is not forcing...without any hope for a game nor a fit, but with a good ♦ length, you may pass !
2 ♥ or 2 ♠ are ambiguous responses, 2 NT is forcing. The responder starts bidding his worst major suit, the opener changes or passes

2 ♥ response It's the weakest response : the responder wishes to stop there if the opener holds a weak 2 ♥ opening hand. Technically, every time the responder has no fit in any of the major suits, he will bid 2 ♥.
2 ♠ response Stop there if the opener holds a weak 2 ♠ opening hand....but the responder is ok for a 3 ♥ contract if the opener has the ♥.
2 NT response relay, forcing for one round without any game ambition (it is similar to the response to a major weak 2 opening). To think of a game, you need a minimum of 15 (or 13-14 HCP well constructed).