Oakland University near Detroit is distributing thousands of hockey pucks to faculty and students. The school's police chief says should a gunman enter a classroom everyone should be ready to throw something - anything - that could distract, stop or hurt the intruder, even a hockey puck.
But can it work? Some students are skeptical.
One student, Adam Kalajian, said, "I find it absurd. What good will it do? I mean there's an armed person coming in - why would you chuck a puck at them? What's it going to do? Nothing."
The university's faculty union believes the pucks can help save lives. It has organized training sessions and bought 2,500 pucks.