None of us kids are swordsman by any means, so these are just for playing around with.
A warning: even though these are toys, they are a bit heavy and you can whack somebody a good one with them if you try. So, probably better for big kids rather than little ones.
This is a fairly quick and easy project ( I think I made both of these in just over an hour, and I was having a conversation at the same time.), but for one step you will need a second pair of hands to help you out.
Step 1: What You Need
thin dowel (I used fiberglass rods because I had some at hand, but wood would probably work better and is generally cheaper.) **(EDIT: Wood is cheaper, but I have recieved advice against using wooden dowels. They break easily and the splintered wood can be dengerous, so it's better to use plastic, fiberglass, or PVC if you can.)
duct tape ( I didn't actually measure how much I used, but it was deffinitely a few yards.)
thin foam yoga/exercise mat (You can get one of these for about $10 and it will yeild at least 3 swords.)
string or twine (Make sure the string you're using is good and strong; you're going to be pulling it very tight.)
saw (This is to cut your dowel to length, so you won't need it if your dowel is already the length you want it. It can be electric or muscle-powered because you're only goint to use it for about 2 seconds.)
hot glue gun and glue stick