Native American practice of demonstrating skill and bravery by touching an enemy, possibly with an ornamented "coup stick", and then escaping.
This is kind of like high-stakes tag, because of course the enemy would rather kill you than let you escape.

Here's a good smattering of facts from http://members.aol.com/jroache/fact019.html:
  • The Plains Indians did this
  • In battle, and for ceremonies, a "Coup Stick" could be used as a staff to touch living enemy...an ultimate insult.
  • Coup was earned for such deeds as killing the enemy, touching the dead enemy, touching the enemy with the hand while he was alive, stealing the enemy's horse, or even being able to touch his tepee.