The Phantom Blade is a life-size reproduction of the weapon (using PVC and thermoplastics) found in the videogame. Along with the hidden blade, it also comes with crossbow arms that is retractable and can fire soft darts. You should not have to worry about actually hurting anyone (unintentionally, at least) since the replica has been tested for reliability and safety. Last but not least, the straps can be adjusted so that it fits all sizes even though it was rated for 17+.
Of course, gamers also get an additional exclusive DLC weapon for Assassin’s Creed Unity. The Phantom Blade comes with a code for the French Cavalry Pistol for all three versions of the videogame, which is coming on the 11th of November. If you haven’t already, go preorder the PlayStation 4, Xbox One and PC game right now with this Amazon link.