Software developer Ubisoft released the first of the "Assassin’s Creed" video games in 2007. In these games, the player takes on the role of Altair, a 12th-century assassin active during the Crusades. Achieving Rank 2 unlocks the “Hidden Blade,” a spring-loaded dagger concealed beneath the left sleeve of Altair’s cloak. Gamers looking for a unique Halloween costume or wanting to attend gaming conventions dressed as Altair can construct their own Hidden Blade to add authenticity to their Assassin attire.
Construct the Blade
Draw the blade’s outline on the foam board using the ruler and pen. In the game, Altair’s blade extends beyond his clenched fist; you can make your blade shorter or longer to suit the dimensions of your forearm and hand.
Cut out the blade from the foam board with the craft knife.
Compress the edges of the blade to give it a sleek, serrated look.
Paint the entire blade with gray or silver and then apply streaks or gradations of black to give it a tarnished look. Altair’s blade has a burnished silver quality throughout and becomes darker toward the base.
Stick two paper fasteners through the blade. Press the first through about 1/2 inch from the base and in the center of the blade. Push the second about 1/2 inch higher and also in the center. Unfold the tab of the second fastener to secure that clip to the blade.
Construct the Wrist Sleeve
Cut a vertical slit down the entire length of three toilet-paper rolls with the craft knife. Set one roll aside. Cut a vertical slit through one of the other two rolls, bisecting the roll for about three-quarters of its length. This slit will provide a groove for the blade to slide through when you spring it open.
Spread the two rolls out flat and lay the cut one on top of the other. Connect them by pushing a paper fastener through all four corners of both rolls and flattening out the tabs of the paper fasteners.
Affix the blade to the sleeve. Place the blade on the top roll so that the unfolded nub of the blade’s paper fastener goes into the vertical slit. Align the blade so that its base and the unfolded fastener are at the beginning of the vertical slit.
Loop a rubber band around the toilet-paper roll’s upper-right corner fastener and the second paper fastener on the blade. Loop another rubber band around the toilet-paper roll’s upper-left corner fastener and the second paper fastener on the blade. Glue the rubber band to these three fasteners.
Pull the blade back toward the lower half of the sleeve, stretching out the rubber bands. Clamp the base of the blade to the bottom of the sleeve with the paper clamp. Tie fishing line to one phalange of the clamp and then thread it around the other end so that when you tug on the line, it pulls the two phalanges of the clamp together and releases the blade.
Finish the Sleeve
Enclose the sleeve with the third toilet paper roll (the one you set aside). Lay the roll on top of the sleeve, concealing the blade inside of it while providing enough room for the blade to move freely. Glue the edges of this roll to the sleeve.
Put the sleeve around your left forearm near the wrist.
Attach a strip of duct tape to the underside of the sleeve with the sticky side facing out. Drape the duct tape across your wrist and then affix the other end of the strip to the other side of the sleeve. Repeat this process at the bottom end of the sleeve, further down on your forearm.
Attach a strip of duct tape with the sticky side down across one of the strips of duct tape, holding the sleeve in place. Repeat this process with the other piece of duct tape that has the sticky side exposed.
Thread the other end of the fishing line to a ring. Remove enough slack from the line so that when your fingers are extended the clamp remains in place. Make a fist to test that the line pulls the clamp open and releases the blade.