You punch another person in the arm and he punchs you in your arm until one of you says stop.
Oh <font color="#FF0000">*censored*</font> i'm the king of that game...but here, we call it Hit-for-hit.
Me too. But at my school we call it "who-the-****-is-so-stupid-that-they'd-hit-each-other-back-and-forth-for-entertainment?-lay-off-the-grass-and-play-a-mans-sport.-like-hopscotch."