From the introduction:
One Piece D20 is a tabletop fantasy game in which the players take on the roles of heroes who form a group (or crew) and set out on dangerous adventures. Helping them tell the story is the Dungeon Master, who decides which threats the player characters face and what sorts of rewards they earn for succeeding at their quests and goals.
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One Piece is a Japanese shōnen manga series written and illustrated by Eiichiro Oda. The first manga chapter was released August 4, 1997 so as of today the series has been around for about 15 years and is still going. There are currently 530+ anime episodes released which follow the manga series, 11 movies (10 of them outside of the canon storyline), and many videos games that are, for the most part, only available in Japan. One Piece is the most popular manga series of all time in Japan and one of the most popular manga series worldwide. It is the highest-selling manga in the history of Weekly Shōnen Jump and has received wide critical acclaim primarily for its art, characterization, humor, and story.
The series follows Monkey D. Luffy as he begins his life as a pirate and starts his adventure to find One Piece. One Piece is a legendary treasure left behind by the famous executed Pirate King Gol D. Roger. Along the way, Luffy makes a lot of friends, which in this series are referred to as “nakama”. Nakama are more than just friends though; it more closely means comrade or extended family member. Some of Luffy’s nakama join his crew and together they go on adventures with the ultimate goal of reaching the end of the Grand Line. The Grand Line is the most dangerous ocean in the world, full of mysterious islands and giant sea monsters. Each crew member has unique combat and non-combat abilities and they all play off each other’s strengths and weaknesses.
User summary:
This product licenses itself under the GNU Free Documentation License Version 1.3, 3 November 2008. However, it in turn appears to be an unlicensed adaptation of the well-known manga to the tabletop.