Pieces of Eight
From YPPedia
Pieces of Eight 
, or PoE, are the basic monetary unit of Puzzle Pirates. There are many ways for pirates to earn PoE, including pillaging, working at and running shoppes, wagering on multiplayer puzzles, and trading goods.
There are as many ways to use and lose PoE as there are to earn it, including losing sea battles to brigands or PvP attacks while pillaging, buying new clothes at the tailor, losing a wager on a multiplayer puzzle game, replacing your sword at the iron monger, buying cannon balls and rum for your pillage, buying your own ship and many more things!
On doubloon oceans, pirates can also use PoE to buy doubloons at the doubloon exchange.
Proper grammatical usage
Only the "pieces" part of the grammatical construction changes in the plural; a pirate may have one Piece of Eight, or many Pieces of Eight. "PoE" is an acceptable abbreviation in either instance, although the form "PoEs" is incorrect.
However, the term poe is more commonly seen than PoE.
