There's a "fair coin", and then there's a "fair flip". It's actually pretty difficult to do a truly "fair flip".
A fair coin is just a coin. There is no such thing as an unfair coin, unless its third side is so huge that it can't be reasonably called a coin.
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A fair coin is just a coin. There is no such thing as an unfair coin, unless its third side is so huge that it can't be reasonably called a coin.