I'm sure we're all familiar with those; found in garages, warehouses, self-storages and the like, and that cannot be opened unless you have a sledge. IMHO, there SHOULD be a way to open them. I mean, they ARE doors, and there are storages where there's stuff locked inside and no other entrances but sledging one of these doors (or a wall). So, I was thinking that maybe we could have them as doors, but with certain characteristics: -Almost Indestructible No amount of head thumping would be enough to breach one of them, and neither can Axes or Crowbars. However, you COULD blow them up with a pipe bomb or similar explosive. Also, once driving cars is added, ramming it with a car could destroy it. (and of course, there's the Sledge, which is kind of a cheat.). -Slow and Noisy to open and close. If you still have power, they could come with a small engine that opens them for you, but makes as much noise as a generator. But, if power's out, you'd had to crank them open and closed, which would make for a rather slow process and still be quite noisy. -Can only be locked with a Padlock. Whenever you wanna lock one of these, you'll need a padlock to do it. And since those aren't exactly common, this would make them very secure against Zed, but easily opened by a Survivor. Overall, the main idea is to make them balanced enough that they make certain places easier or harder to settle in, depending on what you're dealing with.