The MOPEW deck is based on the deck of playing cards in use in the conworld
of the same name, which in turn is based on the most common numeral system.

The numeral system is a duodecimal alphabetic one, using the 36 letters of
the corresponding alphabet as symbols for the digits 0 - 11, the dozens 0 *
12 - 11 * 12 and the grosses 0 * 144 - 11 * 144. Systems for writing numbers
higher than 1727 exist, but are not widespread.

The typical playing cards are a set of two decks, called deck of the Earth
and deck of the Sky / Heavens, distinguished by the artwork, each one
composed by 36 cards marked with a letter / numeric value.

In different times and places, this deck is used as a teaching aid, for
cohoperative games and for gambling.