Chess pieces are often said to value a certain number of pawns. Pawns are worth 1Knights and bishops are worth 3Rooks are worth 5Queens are worth 8Thus making queens the most valuable piece when it...
The term "one piece" is what the series refers to as the treasure left by the previous Pirate King, Gol D. Roger. If you are referring to 'what is the treasure', then nobody knows yet. It is...