I’d like to introduce you to belegarth: http://www.belegarth.com/ It’s a medieval combat society that fights with foam weapons. They have guidelines for fighting and weapon creation, and make everything from bows, to swords, daggers, shields, spears, flails, etc. There are plenty of guides for creating these weapons to be safe for use.

Don’t get me wrong, it can still hurt if you get whacked in the face, but unless said person is completely out of control or has a broken weapon, the worst you could get is a little bruising.

Enjoy!