Sheldon invents his own version of rock-paper-scissors in this episode which includes the addition of a lizard and spock naturally.
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The guys meet Wolowitz's soul mate, Dr. Stephanie Barnett (Sara Rue) in this episode of The Big Bang Theory.
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Leonard goes on a date with Stephanie (Sara Rue), who Wolowitz is convinced is his soul mate.
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The Big Bang Theory Season 2 Episode 8 Quotes

It's very simple. Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and—as it always has—rock crushes scissors

Sheldon

I am not going to watch the Clone Wars TV series until I've seen the Clone Wars movie. I prefer to let George Lucas disappoint me in the order he intended

Sheldon