WaterWar.net

New idea: tri-fold project boards.
You know, the kind that are always being used for Science/History Fairs and such. If you cover them with a waterproof material (garbage bags, etc) it should work well.
Of course, this would depend on a number of variables, including prices of alternatives, such as cardboard boxes, etc, but I have several lying around the house from previous years' projects.
Thoughts? So good or no good?

Most people just use wood boards, which are stronger for more permanent fortifications. And even if you cover cardboard w/ bags, it won't stop all water. Plastic is a better material for fast/cheap fortifications and wood is good for big projects. It depends on what you're doing. In some cases, if you do have a big cardboard structure, you can throw any plastic tarp or tarplike item (like the bags) over it to help improve coverage. However, any such structures or fortifications are still temporary.

So good idea? Yes, for quick builds. You can use such tarps in any situation though (such as a cheap play structure, to cover up holes where enemies can attack from) and I'd say people already do this when necessary.