Non-profit organizations often race the little plastic ducks as fundraisers. Participants usually buy a raffle ticket corresponding with a number on a duck's underside. The first duck to float across the finish line wins.
Duck races in the state include the "Ducktona 500" in Sheboygan Falls and the "Lucky Ducky Derby" in Menomonee Falls.
Republican lawmakers introduced the bill after the state Justice Department warned the village of Mishicot that its annual rubber duck race amounts to illegal gambling.
Walker signed the bill Wednesday.