Here I will show you how to make the piston drawbridge! Now, many of my friends asked why the redstone torches were necessary and why I didn't just wire each piston. The Answer: With so many pistons lined up, it would be very difficult and time consuming to wire each one without a torch. Just look at the pictures and build your own!

Step 1: Dig a 2 block wide hole that is 2 or more blocks deep. You can use any length you want! Then, on both sides of the hole, build a 3 block wide 1 block deep hole on both sides of the original hole.

Step 2: On each inner sides of the second holes, place the desired floor block to hid the trap beneath it. Behind each place a sticky piston. If you want, you can fill your original hole with lava, water, etc.

Step 3: Place a redstone torch behind each piston, causing them to extend and cover the lava pit.

Step 4: Wire each redstone torch to a lever, pressure pad, or button.

Step 5: Test the drawbridge and hide the wiring! Remember, a lever that is on the ground will transmit a signal to the block under it. This makes hiding redstone much easier.

Step 6: If on an anarchy PVP/SMP server, install this trap in your home :) Someone chasing you? Run through your passageway and flip the switch at the other end, and watch your opponent burn in a sea of fire :D