Kids at my school weren't THAT bad - I never saw anyone really badly beaten up. About the worst of it was that we all got the occasional "snake bite." This was accomplished by gripping someone's arm with both hands twisting both ways at the same time (ie, twisting one wrist forwards and one wrist backwards.) It could be moderately painful.
As of the 1950s, Peter and Iona Opie listed this particular torture as a "a Chinese Burn" or "Chinese Twist," and noted that in the U.S. it was known as an "Indian burn" or "Indian torture." My memory of an "Indian Burn" was taking a small piece of yarn, stretched taught, and rubbing it rapidly back and forth across someone's bare arm as though trying to start a fire.
The same torture goes by various names around the world, such as "Indian sunburn" (Canada) and "Policeman's glove" (Bulgaria).
What did you call it?