The defendants, the proprietors of a medical preparation called "The Carbolic Smoke Ball", issued an advertisement in which they offered to pay £100 to any person who contracted the influenza after having used one of their smoke balls in a specified manner and for a specified period. The plaintiff, Mrs Carlill (pictured left, at the age of 87), on the faith of the advertisement bought one of the balls, and used it in the manner and for the period specified, but nevertheless contracted the influenza.

Held, affirming the decision of Hawkins, J., that the above facts established a contract by the defendants to pay the plaintiff £100 in the event which had happened;