BeaverCraft 
Mobstacles
Back in 2007, Captain Slug over at Nerfhaven wrote a post about homemade obstacles for nerf wars:
The bane of Nerf Wars are big empty fields with no cover. They make for boring stand-offs and 90 foot charges that will wear you out really quickly. It took me a few weeks of tinkering and shopping around for parts to find the cheapest solution that's also fairly easy to setup.
These are a great solution for open-field outdoor wars. About a year ago, I started thinking about creating obstacles for indoor Nerf Wars. A friend of mine had organized an indoor war in a school gymnasium, and needed obstacles to make the game interesting. I have been trying a lot of different designs, all of them unsing tarps and PVC, and all of them standalone.
I ulitmately made 10 of the above design, and used them at several indoor and outdoor war. They are functional, and helped a lot for the indoor wars, but are flimsy and unstable. I eventually broke them down into crude tepee shapes, with a tarp wrapped around them. This provided more stability, but greatly reduced the cross-sectional area; still not the solution I want.
After a lot of experimentation, I have synthesized the qualities I'm looking for in a good mobstacle:
- Large cross-sectional area
- Stability - it won't tip over
- Durability
- Easy setup
- Compact storage
- Low price
I highlighted that last one, because it is a hard requirement to fulfill. This is a frustrating project, because I really want to fullfill all the qualities I listed.
Incidentally, inflateable paintball bunkers would be an awesome solution, and they represent an optimal solution in my eyes. Optimal, except for the price tag: a full set of these babies runs over $1000. Maybe someday...
On the subject of paintball, TechPB did a nice show about the history of various paintball gametypes. What I found facinating about this piece was his explanation of the evolution of various forms of cover, and how it affects the flow of the game. A lot of this applies to Nerf, and I took it to heart.
These are the mobstacles I have been using at the Puerto Rican wars, and I figured I should share. They are very cheap to make, and so you can build a lot of them for a war. We play in an open grass field, so artificial obstacles have been vital. They have also held up well in windy weather (a common problem).
You should be able to procure the materials for around ten dollars (I spent $11.50):
- Four 5 foot sections of PVC. I would recommend 3/4" or 1". These act as vertical support. Buy ten foot sections and cut them in half.
- Duct tape to bind the tops together. I suppose a more robust solution would be better, but duct tape has held up well for me.
- About 25 feet of rope
- 6x8 blue tarp
- Two tent stakes
The setup should be fairly self-explanatory. The PVC acts as a frame, with the legs angled slightly inward. The rope his held taught by the stakes, and runs through the eyelets of the top edge of the tarp.
I run the rope through the corner eyelets twice as shown. This holds the tarp tight against the frame, and keeps it from sliding away towards the middle.
I used a rubber mallet to drive plastic camping stakes into each end. It is sort of hidden in the grass, but I tied the rope to the stake with a half-hitch knot. I then tied the lose end of rope to the eyelet at the bottom of the tarp, which keeps it from floping around in the wind.
