We had bottle rocket wars in highschool.
Get a bunch of 3'-6' pvc pipes, cap off one end.
A few thousand doven rockets. Show up to the firework stands at about 11:50pm on the last day they can sell them and you'll get insane deals.
Get some ones older bother to buy a bunch of beer.
Find a big field out in the middle of no where. If there's cows in the field it's just that much more fun
Split off in groups of 3 or more in oppisite ends of the field.....you can figure the rest out
....why are they now illegal in some places?