Hidden Blade, Variant (5e Equipment)
From D&D Wiki
Martial Melee Weapons
This concealed weapon is the signature weapon of the Assassin Brotherhood. It is primarily used for assassinations, as the blade can be controlled by the user to hide under their sleeve and then extend instantly to stab a creature with a single touch. The weapon is also lightweight and retractable, making it perfect for carrying while avoiding detection or chasing a creature. The weapon was first conceived by the assassin Darius, who used it to kill King Xerxes I of Persia. The assassin descendants of Darius then established it as the standard weapon for the Assassin Brotherhood. The weapon can only be obtained through the Brotherhood, and those that sell the weapon are compromising the safety of the Brotherhood, often leading to expulsion, and in rare cases, execution.