Acol

Acol is a bridge bidding system. Originally it was the name of a road in Hampstead, London, where there was a bridge club in which the system started to evolve in the 1930s. The Acol system is continually evolving but the underlying principle is to keep the bidding as natural as possible. It is common in the British Commonwealth but rarely played in America.

The choice between a weak 1NT opening (12-14 points, balanced) and a strong 1NT (15-17 points, balanced) influences much of the rest of the system.