[Zelandakh]

I also learned it as a one round force and it was exposure to North Americans that led to my finding out this was not universal. I was also quite surprised that it had permeated England enough to be included in the EBU MEA file. Anyone playing outside of London still seeing the old-fashioned way on a regular basis? How about Scotland and Wales?

[helene_t]

I think it is universally played as a gf in Dutch Acol. In English Acol, where opener's rebid of his first suit can be a 5-card suit, you are sometimes stuck for a bid with invitational hands that cannot raise, so invitational+ makes sense. In a strong-nt system where opener's suit will almost always be six, gf makes more sense.

I would assume a 1-round force with an generic English club player as partner. Very few bids below 2NT force to game in English Acol by default. Probably most serious Acol pairs play it as a GF, but that is by explicit agreement, not by system default I think. One strong Acol player I once played with liked to play a 2-way 1NT rebid so that rebidding the opening suit showed six, and responder's reverse was a GF.