The signature weapon used by many Assassin's Creed protagonists is the Hidden Blade.
The Hidden Blade is a concealed wrist-mounted weapon associated with the Assassin Brotherhood. It allows an Assassin to perform close-range stealth attacks while keeping the weapon largely out of sight. Its compact design became one of the most recognizable visual symbols of the series.
The weapon appears in the original Assassin's Creed and remains important across many later games. Different protagonists use modified versions suited to their period and equipment. Leonardo da Vinci upgrades Ezio's blades in Assassin's Creed II, while later games add variations such as paired blades and integrated tools.
The Hidden Blade is not the same as every wrist weapon in the franchise. Assassin's Creed III introduces a rope dart as a separate weapon, and Assassin's Creed Unity adds a Phantom Blade that launches projectiles. Those tools complement the Hidden Blade rather than replacing its identity.