I don't know if there's an appropriate Mega-thread for this, so I figured I'd just post a new topic. I was thinking about attempting to make secret passage ways, and I was thinking about how I can make them legitmately secret, and the only way I could think of is to make it indescernable from the regular walls and floors. It's quite simple, really, they're back walls that mesh with real bricks and make it impossible to determine weither it's real or not except by attempting to walk/fall through it. Being able to make bricks that are really not there would allow for some very interesting build options. It's just a fun option I'd like to see, that would make some of my projects possible.