Benjaminised Acol is a convention, modifying the Acol two-level opening bid structure in order to put weak two bids for the major into the system.
Responses after a 2♣ opening Edit
The 2♣ opening forces the responder to bid 2♦ (relay), after which opener bids the suit. Follow-ups are the same in standard Acol with a strong two opening.
Responses after a 2♦ opening Edit
2♥ is the negative (0-7) response. Follow-ups are the same in standard Acol with a 2♣ opening.
Optional NT structure Edit
The 2NT rebid after a 2♣ opening is not defined in the above. Optionally, the notrump structure may be modified as follows: