This trap is easy to set up and build, but you must make sure to make it like what is shown in the video. I'm not making a How-to-make video unless it is really necessary. You can see all the components in the video, and also how to reset the machine.

(This machine is automatic! Watch the video, it is not a triggered trap, it is always opening and closing!)

Additional Notes

Good for PVP and multiplayer, or just killing some animals. Impossible for people to get through, and they dont have to trigger any button in order to die, it may be basic, but its for sure to work. Hide the components in a building so enemies can't destroy the redstone!