What is the name of the Assassin order's hidden blade in Assassin's Creed?

The Assassin order's signature concealed weapon in Assassin's Creed is the Hidden Blade.

The Hidden Blade is a retractable wrist-mounted blade used for discreet assassinations. It is one of the most recognizable pieces of equipment in the series and appears in many historical periods. Early games depict Assassins using a version that extends from beneath the forearm, while later entries add upgrades and alternative mechanisms.

The weapon is closely associated with the Assassin Brotherhood's emphasis on stealth. In the first game, Altaïr initially uses a design that requires sacrificing a finger, although later modifications remove that requirement. Ezio receives a dual Hidden Blade upgrade from Leonardo da Vinci in Assassin's Creed II.

The Phantom Blade in Assassin's Creed Unity is a different weapon: it combines a concealed blade with a ranged mechanism. That distinction matters because the series includes many specialized tools, but the classic wrist weapon is specifically called the Hidden Blade.