The story
Early American baseball was played in open-air parks, and nobody could control the weather. A downpour could wash out a game that fans had already paid to see.
Some clubs began giving those fans tickets good for another game. The practice was being reported by 1870, and the name rain check was in print by 1877. One account praised the St. Louis club as “the only nine in the league which gives its patrons the right to see a full game or no pay.”
The system had a weak spot. When the checks were handed out at the gate as people left, fence-climbers and freeloaders could collect them too. Around 1889, ballparks moved to a better idea: a stub on the original ticket served as the rain check.
From the ballpark, the idea spread. Other outdoor entertainments used rain checks, and later so did stores, promising a sale price on an item that had run out. In everyday talk, a rain check became a friendly promise to say yes some other time.
