Last year a high school student was injured during a Halloween prank in Massachusetts. Apparently one of his teachers was wearing a mask and waiving a chain saw in the air caused this teen to run for his life! Unfortunately the boy fell while he was running away resulting in a fractured bone and knee injury causing him to be on crutches and miss out on participating. The boy is seeking $100,000 in damages!
The moral of the story is have fun but don't make it too scary! You never know where an innocent joke could have you facing a large liability claim.