This is a school warfare weapon but don't shoot it At school
Step 1: Taking Apart the Pen
For this you will need a pen like the one in the picture.next you will need a rubber band.now you have all the parts you need
Step 2: The Body
Using the cover part at the front of the pen later make a hole in the middle the body tube with any sharp object but big enough so that the cover part of the pen will go in.if it won't stay in use hot glue to keep it in place.
Step 3: The Firing Cord
This is when you will cut two semi-deep notches in the side so you can fit in the rubber band.once you have finished putting the rubber band in place you are almost finished
Step 4: The Ammo
The last part you should have is that inner part of the pen and that is your arrow.