Imperial Seal

The Imperial Seal of China, also known as either the Jade Seal (玉璽, Yuxi/Gyokuji) or the Heirloom Seal of the Realm (傳國璽, Chuanguoxi/Tengokuji) and Imperial Jade Seal, is a carved seal made from the historically famous He Shi Bi jade. It was once believed that those who possessed this seal would be granted the Mandate of Heaven, a sign of rulership over the Middle Kingdom.

This particular seal was crafted in 221 BC when Shi Huangdi toppled the six Warring States and unified China under his rule. He had his chancellor, Li Si, inscribe it with the words: "Receive the mandate from heaven. Enjoy longevity and eternal prosperity." The seal was described to have been four inches at the base with an upper ring carved in the likeness of five interlaced dragons. It is also said to have a chipped corner repaired with gold due to Han Empress Wang throwing it on the ground in response to the demands of Wang Mang.

The usage of seals were primarily used to affix documents, literary works, and various paintings. There was a time when all seals were referred to as xi until the birth of the Qin Dynasty made the word exclusive to seals used by the emperor. Early seals were mostly created from jade, bronze, or other precious metals; later eras used materials such ivory and porcelain in the crafting process. The creation of seals was considered a form of art.

The Imperial Seal was passed on from one successor to another until it was deemed missing during the history of the Five Dynasties and Ten Kingdoms Period. There are many theories as to how it disappeared, but none have been proven so far. The seal was never found and its location remains a mystery to this day.

Roles in Games
Every Koei game based on Romance of the Three Kingdoms portrays the Imperial Seal as a source of conflict between China's rivaling warlords. Upon being discovered in 191 AD by Sun Jian at Luoyang, he handed it over to his lord Yuan Shu who used it as a legitimate claim to start his own dynasty in 197. When the other warlords turned on Yuan Shu and defeated him, the seal was then given to Emperor Xian who in turn played the role of puppet ruler for Cao Cao.

In the Dynasty Warriors series, the seal is a power-up item that fully replenishes the user's Musou and keeps it unlimited for ten seconds, though as of the seventh installment due to the reworking of the Musou gauge, it instead fills the player's Musou Gauge to the maximum current amount of segments as opposed to by one (though it keeps its old function in the entirety of the Warriors Orochi series).

Romance of the Three Kingdoms titles refer to it as the Hereditary Seal which helps players shave off the requirements needed in becoming emperor.

While the story behind the Imperial Seal is shared by the aforementioned games, Kessen II offers a different tale on its whereabouts. Having been entrusted with it by the child emperor, Diao Chan hides the seal until someone worthy can rightfully claim it. Her knowledge of the artifact's location is discovered by Cao Cao's priestess Himiko which leads to the dancer's abduction.