Hello from Hero Dad*, i'd like to give you some simple tips on how to throw a rockin' Nerf gun birthday party. Essentially you just need to transform your backyard into a Nerf battlefield and the kids will do the rest. This is a sure fire way to have tons of fun at your next birthday party (ideal age is 6 to 12) for not much money (although there is a bit of work involved) using some easy to build Nerf games and Nerf battle modular forts.
*Hero Dad defined: any dad trying to impress his kids with some type of act or service
Lots of card board boxes (the bigger the better) I used 48x24x24
sharp razor blade or box knife
spray paint for camo
Step 1: Building Nerf Shooting Forts
Step 2: More Nerf Forts
Here is another example of some Nerf shooting forts (aka Nerf pill box) that will help transform you lowly backyard to a super cool Nerf battlefield. For this barrier simply build a box (48x24x24). Then cut one side and fold it out, cut a viewing slot, so that it provides more protection from the enemy. I added some door windows for extra protection from enemy dart (this is easily done by using duct tape to make a simple hinge)
All of these "forts" were modular so they are easily moved around the yard. I added spray paint camo to add to the coolness factor.