Minecraft: Lever Combination Lock

 

Welcome, Rovers!  This simple town is being built from the ground up in Creative Mode to test out a few different red stone contraptions.  I wanted to share these contraptions with you.  

Hopefully my breakdowns make everything much clearer, because red stone can be rather confusing.  Lets start with a programmable door lock.  The benefit of redstone is that it enables you to automate things, alter things, and generally have fun.

You may ask yourself why you would want a locked door at all in a game like Minecraft.  The more you play on public servers, the more you'll see a need for it.  As you collect the rarer materials such as gold and diamonds, you'll want to keep it safe from pilferers and vagabonds.

We'll be learning how to use the programmable lock detailed here by Youtuber MrCrayFish:  https://www.youtube.com/watch?v=01AtBtaH4bo&list=PL2FC870D708AECBBA&index=19

 

This is what the lock looks like from the outside.  You can make is as many levers as you would like.  When you set it up you need to place the levers at the second block from the ground.  The only key, for me, would be to end the lever line 3 spaces from the door.

Now here's the key!  Directly behind any lever that is angled down you need to place a red stone torch.  You do this because by default any lever that has been switched down turns the block it is attached to ON.   When you then place a redstone torch on the backside, it changes that input to off.  Place some redstone dust on the ground under the torch to create a circuit.

On the other hand, when a lever is in the up position, the block behind it is turned off.  Behind that, place a block with some redstone dust on top.

The end result of the circuit behind the levers is you want the whole thing to be dark.  If it is lit up, then you have a switch out of place.

The reason you want the lever circuit dark is the bit pictured above.  If you place the red stone torch and red stone to the door you'll see it light up.  This is the same as the switches before.  The red stone torch switches the input.  So if the circuit going in is on, the torch will turn it off.  If the circuit going in is off, it will turn it on.

The red stone dust then carries this to the door.

If the levers are correct, the result is an open door as pictured.  If one is out of place, it will turn everything off.

One last aside about this locking mechanism.  It can only create a maximum number of combinations.  So if you have 2 levers, there are only 4 combinations.  Obviously someone could break into your room with a few seconds effort.

The number of combinations comes out to 2^X.  So if you use 8 levers, there are 256 combinations.  If you use 16 (an absurd number to toggle all the time) then there would be over 65,000.

If you only toggle the last lever, it will defeat the purpose of the lock.  The first thing someone does when trying to break your lock should be toggling one lever at a time.  Leaving most of the combination in place defeats the complexity.

A last concern, if you play this on an un-modded server people are just going through the wall.  There are servers that establish protected plots for players that don't allow destruction by other users.  There are the places where locks like these can shine.