Tutorials/Breaking bedrock

Bedrock is a block that is unbreakable in Survival mode. Even so, it is still possible to break the unbreakable in Survival mode without cheats. These use glitch and bug exploits to achieve this, so these methods could be rendered useless at any update. Breaking bedrock is also more difficult than phasing through the bedrock, both of which is covered in this. Note that these methods can also be used to break other unbreakable blocks (though bedrock is the most useful) and regular breakable blocks (the player will not be able to collect any of the blocks broken, and they are much easier to break using tools).

Why Bother?
It may seem pointless to go through the effort of going through or breaking bedrock, but it is actually quite useful. The most common use of these techniques is to make an easy access point to the top half of the Nether by phasing through the top layer of bedrock and then breaking the bedrock to put up a ladder or elevator to the top. Breaking bedrock is also useful if the player wants to fall into the void in the Overworld or Nether. It is also useful for breaking some of the blocks on the end gateways and the return portal in the End. These same techniques can also be used to break the frames around the end portal in a stronghold.

Phasing Through the Bedrock
This section is about going through the bedrock. The only logical reason to do this instead of breaking the bedrock is going up through the bedrock in the Nether ceiling.

Method 1
This method requires ender pearls. It was much easier to do in update 1.8, but is still possible in later versions.

To use this method, you will need the following materials:
 * lots and lots of ender pearls. It is recommended to have at least 8.

Dig up to where the player would be "bumping" its head on the top layer of bedrock (on y = 127). Then, look straight up and throw the ender pearls as quickly as you can. This is more difficult to do in versions 1.9 and above due to the item cool-down. It works by having one of the ender pearls glitch and teleport the player into the block such that when the next ender pearl is thrown, it goes above the block and teleports the player to the top of the block.

Pros:
 * It is easy to get all the materials needed.
 * It is easy to do once you get the hang of it.

Cons:
 * It may take many stacks of ender pearls to work.
 * There is a possibility of death due to damage from ender pearls.

Method 2
This method requires that the player has already journeyed to the End.

To use this method, you need the following materials:
 * at least 1 chorus fruit
 * at most 2,048 blocks (32 stacks) of any kind

First, fill in an area that is 8 blocks in each direction surrounding the player. I said "at most" because the netherrack and bedrock that generates naturally can be used to fill in this region. Once this happens, stand in the middle of this filled-in area, and record your coordinates. Then, eat the chorus fruit. If the player is not teleported on top of the bedrock, eat another chorus fruit until you are successful. It works using a chorus fruit's teleporting ability and removing all other valid places for the player to teleport to.

Pros:
 * It can be reversed by placing another region of blocks with 8 blocks in each direction on top of the bedrock ceiling, and then eating another chorus fruit.
 * It is easy to accomplish.

Cons:
 * It requires that the player has already journeyed to the outer End islands to harvest chorus fruit.
 * The chance of success is random, so it is possible that it will take a huge quantity of chorus fruit.

Method 3
This method is by far the cheapest, but also has the highest chance of death.

To use this method, you need the following materials:
 * 1 rail (any kind)
 * 1 block (if needed)
 * 1 minecart
 * 1-2 ender pearls
 * Helmet enchanted with Respiration (recommended but not required)

Dig up to the highest level of bedrock (y = 127). Place a block (if needed) two blocks below it, and then place the rail on top of this block. There should be no gap between the rail and the upper layer of bedrock. Next, place a minecart on the rail. This is where it gets dangerous, and where the Respiration-enchanted helmet. Get inside the minecart and quickly dismount it. The player should be suffocating in the bedrock layer. Next, hold down the "jump" key and throw an ender pearl directly up. In case of this failing, throw another ender pearl directly upward. It works by having the minecart dismount the player in a position where the player will be able to jump and see the top of the bedrock. The ender pearls move the player to the top.

Pros:
 * It is very cheap and could be done early in the game.
 * It is easy to accomplish.

Cons:
 * If the player runs out of ender pearls, he or she is stuck in the bedrock with absolutely no method of escape.
 * There is an extremely high possibility of death, and the drops will most likely land on top of the bedrock.

Breaking the Bedrock
Breaking bedrock is a very complex and involved process. There are currently two common methods to do this.

Method 1
This method can seem needlessly complex, especially since it will only break one block that is adjacent to the ceiling, and it only works from above. These are the materials you will need:
 * 2 sticky pistons
 * 2 normal pistons [note 1]
 * 10 redstone repeaters
 * 1 activator rail
 * 4 cobblestone walls [note 2]
 * 2 TNT minecart [note 2]
 * 10 obsidian
 * 2 redstone blocks
 * 5 redstone
 * 1 lever
 * Blocks of any kind for convenience.

Note 1: one of these pistons will be sacrificed. Note 2: these will explode. Do not plan to get them back.

With these materials at hand, this is what you do. Pictures are provided at each step because it is easy to make a mistake, which would mean having to start over. 1. Place the 2 sticky pistons perpendicular to each other and facing the block that you wish to remove. In the picture, the block being broken is marked with glowstone above it

2. Three blocks away, diagonally away from the pistons, place the activator rail. Marker iron blocks are placed for convenience.

3. Place obsidian starting from behind the activator rail and going until the closest piston.

4. Place a lever against the obsidian behind the activator rail such that the lever powers the rail.

5. Place 5 repeaters leading away from the lever, a block in front of that chain, and another 5 repeaters going towards the pistons. Set the delay on all of these to their maximum.

6. At the end of this repeater chain, place a block. Place another block behind the closest piston and a redstone between the block and the block behind the piston.

7. Place two cobblestone walls on the remaining two sides of the block above the one that you are trying to break.

8. Place a TNT minecart on the activator rail and flip the lever. Stand back and watch the piston head get blown off. It is crucial that you do not turn off the lever. 

9. Place a redstone block diagonally up from the piston away from the block you are trying to break. Turn off the lever.

10. Place an obsidian block between the two pistons. The redstone should be able to power both pistons at the same time.

11. Repeat steps 7-9.

12. Now that you have two headless sticky pistons, break all of the blocks that you just placed except the headless pistons and the redstone blocks.

13. Place a piston facing down one block away from the headless pistons directly on top of the bedrock. This will require the use of another piston.

14. Break the piston that you used to push the downwards-facing piston into position and place this piston on top of the block you are trying to place, facing upwards.

15. Move to a place where the headless piston on your left is facing the line of normal pistons facing up or down.

16. Place a repeater pointing to the upwards-facing piston, one redstone, and then another repeater facing the redstone and parallel to the left headless piston.

17. Place a repeater set to a delay of 2 facing the left piston and two repeaters on the default setting lined up and pointing into the right piston.

18. Connect the repeaters with redstone until you run out. In the missing spot, place a lever and power it.

19. With the redstone lines powered, break the redstone blocks next to the headless pistons.

20. Turn off the lever. All should return to normal, with the sticky pistons getting their heads back, but the downwards-facing piston would have mysteriously disappeared, and there is a hole in the bedrock below the upwards-facing piston.

The way this method works is manipulating the explosion power of the TNT minecart to blow up the head of the piston, but not the base of it, combined with perfect timing, causing the piston to extend at the exact same time as the TNT minecart explodes. I do not understand what goes on with the headless pistons or why they end up destroying the bedrock and sacrificing a piston. Any knowledge of this matter is very welcome!

Pros:
 * It can be done early in the game, since it does not require many resources.
 * It can be done quickly after some practice.

Cons:
 * It is insanely complicated, and one mistake means having to completely start over.
 * It only breaks one block directly below the setup.

Method 2a
There's two variations of this method. Here is the first variation.

This method is much simpler, but it requires more resources. These are the minimum materials you will need to break one block:
 * One dragon egg
 * One piston
 * One redstone torch
 * 31-481 redstone [note 1]
 * 33-513 blocks of choice [note 1]
 * 2-32 redstone repeaters [note 1]
 * 1 lever

Note 1: this amount varies greatly on render distance. The amount of redstone you will need is 15 times the render distance. The number of repeaters you will need is the same as the render distance. The number of blocks you will need is 16 times the render distance, plus 1.

This method is incredibly easy to do, but time-consuming. This is all you need to do: 1. Place one block of choice. 2. Place a redstone torch on the side of this block. 3. Place a piston on top of the redstone torch. 4. Place the dragon egg on top of the piston arm. This dragon egg should be exactly above the block you are trying to break. 5. Place the remaining blocks in a straight line with redstone on top of it. Place repeaters every 16 blocks of this redstone line. At the other end of this, place a lever. 6. Power the lever, wait five seconds, then depower it. 7. Walk back to find the dragon egg taking up the space of the broken block. This works because the dragon egg is dropped in the "lazy chunks". Lazy chunks are a region two chunks wide that are partly loaded and have not yet been unloaded. Redstone still works, but falling sand entities fall instantly. Dragon eggs have the strange property where they replace the block they fall on with itself, if they fall in the lazy chunks.

Pros:
 * It can be expanded to break more bedrock in one go, if the player manages to obtain more dragon eggs.
 * Since it uses a falling block, the player can construct this any number of blocks above the one being broken.

Cons:
 * It cannot be used to break a block on the bottom layer of the world, since it requires the dragon egg to fall on a block below the one being broken.
 * On multiplayer, other players may end up loading the chunks where this is happening, causing it to fail.

Method 2b
This method is exactly like Method 2a, but it is simpler. These are the materials you need:
 * One dragon egg
 * Stuff for the lazy-chunk detector

To break the bedrock, do this: 1. Build this contraption and turn it on. 2. Walk away so that you can't see the contraption. 3. Walk back.

If this fails to drop the dragon egg, walk farther away. This works in exactly the same way as Method 2a, except it utilizes an automatic lazy chunk detector to drop the dragon egg for you. The pros and cons of using this method is the same as in Method 2a.

Method 3
This method requires a hole in the bedrock directly above the Nether portal that brought you to the Nether. It only works with the ceiling of the Nether, and requires that there are no other portals with 16 blocks in the Nether or 128 blocks in the Overworld. These are the materials you will need:
 * A lot of transparent, non-spawnable blocks (glass, slabs, etc) [note 1]

Note 1: this amount can change drastically depending on the situation.

1. Place the non-spawnable blocks on every top surface of every block within 16 blocks horizontally and all the way up and down between the bedrock barriers. 2. Break the Nether portal that brought the player to the Nether. 3. Build another Nether portal at least 16 blocks away and use it to travel back to the Overworld. 4. Go back to the original portal and use it to go back to the Nether. This portal should spawn at the Nether ceiling, breaking some more of the bedrock. Repeat this to break more bedrock.

This method works by removing all of the valid places for a Nether portal. It forces the portal to generate in the bedrock, replacing some of it with the obsidian frame.

Pros:
 * It is incredibly easy to accomplish.
 * It is very fast.

Cons:
 * It requires a lot of work to prepare the area.
 * It requires the player to have already used one of the methods above to break the bedrock needed to utilize this.