Hi all. I'm in charge of a college physics club, and we want to have
an activity where we all make our own simple laser tag guns and run
around the science building late one night having a grand melee.

Now, the problem is that word "simple." I've found countless designs
out there on the internet, with everybody trying to outdo everybody
else and make better and more sophisticated designs with all sorts of
functions. Our guns don't need an ammo counter or hit counter, or any
other special features. They don't even need to look like guns or be
housed in gun casings because we just want to try to make these as
cheaply as possible, because the club will be paying for parts. We
want to make them from scratch.

Now, I know what you're thinking--"that won't be any fun without a hit
counter!" But here's what I'm thinking--what if you have two bases
and try to make it from one to the other, and if you get hit then your
gun stops working completely, so you have to go back to your own base
to respawn. Maybe when you get there you plug your gun in for a
second or something. The bases, however, are sensors with hit
counters so they keep track of how many times they were hit. At the
end of 45 minutes, the team with the most hits on their base loses.

Does anyone know of any plans on the internet like this, or even
anything along these lines, either plans for DIY laser tag with just
the bare bones, or plans to make a set of guns ridiculously cheaply?
I've looked around but had no luck yet. If so it'd make a great and
interesting physics club activity not just for us but for any physics
club.

Thanks in advance!
- David