To play Moon Pennies, everything you can buy with your "Moon Pennies" has to have a double letter.
Every sentence must start with "With my Moon Pennies I can buy... but not a..." You have to say two similar items but one has to have two of the same letters in a row. See some the examples below (courtesy of a Subeta.net contributor):
With my Moon Pennies I can buy a cookie but no sugar.
With my Moon Pennies I can buy a pool but no water.
With my Moon Pennies I can buy bubblegum but no flavor.
With my Moon Pennies I can buy a floor but no house.
With my Moon Pennies I can buy shampoo but no conditioner.
With my Moon Pennies I can buy a poll but no flag.
With my Moon Pennies I can buy a princess but not a prince.
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