acol

Acol is a traditional contract bridge bidding system that originated in the United Kingdom during the 1920s and is named for the Acol Bridge Club in London. It became one of the most widely used natural bidding systems in Britain and remains influential in club play, particularly in the British and Commonwealth bridge communities.

The system is characterized by natural and descriptive bidding. Openings at the one level typically show four or more cards in the suit and a standard opening-point range, with the four-card major suits emphasized in opening bids. The 1NT opening is commonly around 12 to 14 high-card points. Acol also traditionally includes weak-two openings at the two level in major suits, describing a five-card or longer suit with a weak point count to pre-empt and destabilize the opponents’ bidding. Many Acol agreements use straightforward, context-driven responses rather than heavily artificial conventions.

Over the decades, Acol has evolved into several variants and has been integrated with modern conventions, including occasional game-forcing approaches and one-over-one-style agreements in some partnerships. While less dominant at the highest levels of international competition today, it remains a foundational framework in many clubs and teaching programs in the UK and elsewhere, valued for its clarity and straightforwardness.

See also: bridge bidding systems, British bridge.