- "The King's Sword once belonged to the Prince's father. It is durable and emits a bright light that effects the light sensitive Reptus. Capable of killing enemies in a single blow, the sword is one of the most powerful weapons in the game."
- —Official Booklet Description
The King's Sword, once the sword of the late Sharaman, has the ability to kill enemies in one blow. The light it gives off in the dark suggests it may be enchanted in the same sense as the Sword of the Enlightened Warrior from The Sands of Time. Like the aformentioned weapon, it can destroy fractured wall with few well place strikes. It is the only weapon the Prince does not discard after finding it.
Events of The Two Thrones
When the Prince fell into the well he found the body of his father and his sword. Taking it, the Prince resolves to face his problems head on, and live with the future he created rather than running away from it as he had done for seven years. This gives him the strength to suppress the Dark Prince.
The sword itself is inscribed with markings that glow with a bright light, which helped the Prince to find his way into the catacombs under the palace. During the final battle with Zurvan, the Prince, after cutting off his wings, plunges the King's Sword sword through the Vizier's chest. This wounded Zurvan, but did not kill him. Zurvan moved upward away to attempt to heal himself, but the Prince was able to follow him and finish him off with the Dagger of Time, thus ending the Vizier's evil reign.
The King's Sword is the strongest weapon in The Two Thrones. When the Prince is wielding it, he can break walls that are already damaged and can kill any sand monster, except for the Vizier in one hit.
Enemies they will not drop any Sand if killed by the Sword except for Thralls. The best thing is to use a combo that utilizes both the Dagger of Time and the King's Sword. The sword becomes a permanent weapon; as such, the Prince can no longer pick up fallen weapons nor throw away the King's Sword.
- The King's Sword appears as a usable weapon in the first episode of the Assassin's Creed Odyssey DLC Legacy of the First Blade, called "The Sword of Kings" and awarded upon defeating the episode's main villain, Amorges.