2003 · ソースブック（プレイを拡張するルール／オプション）
Secrets of the Dragon
A dual-system sourcebook for Legend of the Five Rings and Oriental Adventures examining the Dragon Clan of Rokugan. It details the clan’s history, traditions, provinces, families, tattooed monk orders, notable figures, and perspective on the Empire’s past. Players gain new options including Kitsuki courtier abilities, swordsman techniques, mystical tattoos, feats, and other character abilities. The book also describes the dangerous Tamori Tunnels and reveals the clan’s hidden mysteries. Primarily intended as a Game Master resource, it includes campaign material, adventure ideas, spoiler information, new fiction, and setting details that can be adapted to other d20 campaigns.
ゲーム情報（人数、プレイ時間、対象年齢、クレジット）の出典：BoardGameGeek。