While you were explaining the Mannequin Challenge to your grandmother at the Thanksgiving dinner table, the teens of America had already moved on to start a brand new viral trend: the Backpack Challenge.

The premise of the Backpack Challenge is simple. Two rows of people line up with their backpacks in hand, presumably full of heavy textbooks. Then one unlucky chump tries to run between the lines as his friends mercilessly hurl the backpacks at him until he falls over.

The challenge has been compared to an Apache line, a gang initiation technique in which a recruit would similarly have to run between two lines. Instead of backpacks, though, the person would have to dodge and survive more direct violence in the form of punches, kicks, and even baseball bats. The Apache line also inspired a dance phenomenon of the same name, where break dancers would “battle” in a similar two-line formation.

The Backpack Challenge, though, is said to have been invented by students at Palmdale High School in California, and the original video was posted by Twitter user Abucci Wood. It has since been recreated by students all over the country.

If textbooks are half as heavy as they were when I was in high school, the Backpack Challenge looks brutal. It’s unlikely that quite as many celebrities will recreate this as they have past viral challenges. But given the smiles of the runner and the laughs that erupt at the end of each video, the Backpack Challenge seems to be a bit of (sado-masochistic) fun.

Here are some of the best Backpack Challenges posted online so far. Unless you want a body full of bruises and potential injury, I don’t recommend you recreate this one at home.

c5NXZ1NzE6tx5MFAg4luiJNZAmniox7x