One-Armed Bandit- A slang term for a slot machine, primarily used in the USA. The term is based on a gaming device from 19th and 20th century, slot machines which were operated by depositing a coin and pulling a lever (the arm) on the right side of the machine, to generate an outcome. Since the late 20th century slots have been updated to allow play using electronic credits, instead of coins, buttons instead of levers.  These changes and the rise of the internet has led to online casino slot games. This change in the way most people play slots has led to a decrease in the popularity of this term.

 

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