I've invented a new door trap. It's partially a basic far-fall trap, but ultimately is a new trap made by me. I'm building a fortress for a Staff EOI in this world, so sorry about the ugly unfinished fortress wall. It's a WIP. However, near the spawnpoint of the world is the fortress, and at one side is the front entrance. To access the world, go to your launcher, edit profile, choose to open Game Dir, then go into your saves folder. Drag and Drop the attached file, and it's an accessible world in minecraft release 1.10. The door trap is there, mess about with it and disect it to see what it does for your own sake. IDGAF. But please don't take my fortress and/or trap and plagiarize it.

https://drive.google.com/open?id=0BxykWsvCulb0YkdHS3VkenZGZEk

This door trap is known as the SEKAD, the Selective Entrance Kill-or-Access Doorway, intellectual property of BLU3_M00N. Trademark pending. :p