While this perhaps isn't the correct place to discuss this, I have made a number of bridges where practically all of the deck supports have broken and my bridge still worked exactly the way I intended. It happens on my ultra-cool rope bridges (no support underneath or over, just cables running along the sides of the decking connecting the pieces together). I have had working bridges with over 1,000 broken links from building that way. I don't think it would be a good idea to allow deck supports to break in competitions though (for one thing, it is often very difficult to tell exactly what pieces broke, especially as the number of broken links increases).