Slots

A slot machine or simply slot is a casino gambling machine with three or more reels which spin when a button is pushed. Slot machines are also known as one-armed bandits because they were originally operated by a lever on the side of the machine (the one arm) instead of a button on the front panel, and because of their ability to leave the gamer penniless.

In Fallout: New Vegas, playing 10 spins of slots gives you the One Armed Bandit achievement/trophy.