In different versions of Minecraft there have been various exploits that allowed a player to break/replace unbreakable blocks in survival.
Current Methods Edit
Headless Pistons Edit
There are methods to get headless pistons in survival. Normal headless pistons have the property, that they delete the block directly in front of them when they retract. This can be used to break bedrock.
The main problem with this method is, that while it is easy to first make a headless piston and then place a bedrock block in front of it (in creative mode or using some other obscure survival friendly method ), it is very difficult to have a naturally generated bedrock block, and then make a normal headless piston face into that bedrock block. It is however possible. (And the description of that is TODO)
Dragon Eggs (broken in 1.13) Edit
 Gravity affected Blocks in lazy-Chunks by RedstoneSpire
Gravity affected blocks have a different behavior in non-entity-processing chunks than in entity-processing chunks. Due to a bug in the dragon egg code, dragon eggs in non-entity-processing chunks will delete any block they fall on in non-entity-processing chunks. This can be used to delete bedrock.
Here´s a video demonstrating this: https://youtu.be/j33vAgJdDrQ
A more in-depth description of this is TODO.
End Crystals Edit
How to keep the old Endportal by Panda4994
This only works in The End, because that is where ender crystals generate fire.
We push the ender crystal into bedrock when it is in lazy chunks, so it doesn't explode (as it doesn't get ticked). When it's inside the bedrock we make the chunk an entity processing chunk again and it places the fire which "breaks"/replaces the bedrock.
This video by Panda4994 also explains how to keep the old end portal in 1.9 and how to spawn the new portal at a desired Y-level, which is as cool as breaking bedrock, too.
Nether Portals Edit
When a nether portal generates, it replaces a 1x4 area of the floor with obsidian. This mechanic can be used to break 1x4 areas of bedrock.
By removing all valid locations, except for a certain spot, where nether portals can generate, it is possible to force the portal to generate in that location. This deletes the blocks the portal forms on.
Jungle Trees Edit
Large jungle trees can only grow if there is a 5x5 area free of blocks, centred on the northwestern sapling, meaning that no bedrock can be broken in this area. Also, the highest branches can only form 4 blocks below the lowest block in the 5x5 area, meaning that there must be at least 4 blocks of space above the tree on the layer of bedrock you want to break.
Branches always generate in a circle centred on the southeastern corner of the tree. On the 5th layer of the tree, they can generate in a radius of 3 blocks. On the 6th-28th layers, branches will generate in a radius of 4 blocks. On the 29th layer (maximum tree height) the branches grow in the same area as the previous layer, but can only form on the circumference, in a ring.
Bedrock can only be broken in the south and east directions using this method, and requires at least a 5x5 column of air next to it. This means it can only be used for the nether roof if you already have a 5x5 hole in it. It can also be used to break specific blocks, while keeping others safe, meaning it can be used to help build wither cages.
If you only wish to break a layer of bedrock, while keeping lower layers, you can utilise the lowest branches, which grow on the 5th layer. Make sure there are only 4 blocks of air between your dirt and the bedrock you want to break. Then place a block 13 blocks above the dirt. This will force the tree to grow as low as possible, meaning the branches are more likely to grow on the lowest layer.
In order to break lower layers of bedrock while keeping higher layers safe, simply place the dirt 5 blocks below the lowest bedrock you want to break, and then place a block 5 blocks above the highest bedrock you want to break, in order to restrict the tree height.
- Gold = Branches can not grow, blocks prevent tree growth.
- Iron = Branches can grow, blocks prevent tree growth.
- Diamond = Branches can grow.
Old Methods Edit
Beds (1.8 to 1.8.1) Edit
In 1.8 there was a glitch that made it possible to delete blocks by placing a bed on top of the hitbox of a dead bush, grass, fern or vines. The base of the bed would replace the plant, and the head of the bed would replace any block next to it. It would only work if there were blocks beneath the bed for it to be placed on.
This broke the bedrock from the side, and required very little free space. It couldn't break through the roof of the nether, but could be used if there was already a hole. It could not be used for y-0 bedrock.
Tree Branches (up to 1.8.1) Edit
From the introduction of large oak trees in Alpha until 1.8.2-pre 4, there was glitch that caused their branches to replace certain blocks, including bedrock. Upon the introduction of dark oak trees in 1.7, the glitch also affected their branches.
Dark Oak Trees (1.7 to 1.8.1) Edit
This was probably the most widely used method ever for breaking bedrock. By planting dark oak saplings under some logs (of any type and orientation) causes some variants of the dark oak trees to grow with the top of the tree at the level of the saplings. This caused the branches to replace blocks below the level of the saplings. The logs could replace blocks in a 4x4x4 area, starting from the level of the dirt the saplings were placed on. Unfortunately, however, they could not remove any blocks directly below the dirt, so in order to create a clean hole through bedrock with nothing in the middle, you'd need to make it at least 6x6.
This method broke bedrock from above, and was most widely used for breaking through the nether roof, although it could also be used to break the floor of the nether and overworld.
Large Oak Trees Edit
In versions before 1.8, large oak trees were able to replace any blocks directly adjacent to the trunk with logs. The logs could destroy any block adjacent to the trunk in an 8 block high area, starting 3 blocks above the sapling. If there was a block above the tree, the highest could spawn 4 blocks below it.
This technique was very impractical because it took a lot of time and effort to break specific blocks using this method due to the branch generation being random. Also, it could only break bedrock to the side, and needed a large clearance area for the tree to grow. However, if you already had a hold in the nether roof, it could theoretically be used to enlarge that hole.
Skulls (1.7.6 to 1.7.10) Edit
Between 1.7.6 and 1.7.10 there was a glitch that meant that if you placed a skull on the side of a non-full block, it would replace the adjacent block. It would work with any block that skulls could be placed on.
|Place skull on top of this block to break from below||Place skull on side of this block to break sideways|
|Pressure plates||Pressure plates|
|Daylight sensors||Fence gates|
This worked with any type of skull, however at the time, wither skeleton skulls were the only skulls available in survival. It could break bedrock from below and the side, but not from above, and only required 1 block of space next to the bedrock. This meant it could break any bedrock except y-0 bedrock. Although even y-0 bedrock could be broken if there was already a hole to expand from.
Arrows (1.7 to 1.7.5) Edit
In versions before 1.7.6 and 14w17a, there was a glitch involving arrows that enabled two different methods of breaking bedrock. They were both fixed in the same patch.
It involved glitched arrows storing the wrong coordinates of the block they were last on. When they landed, they would update the metadata of the wrong block, and this enabled bedrock breaking because they could create headless pistons and replace blocks with ignited TNT.
Headless Pistons Edit
In March 2014, oldGanon discovered a new way to change block metadata. In order to change the metadata of a block, arrows would be shot inside it and then another arrow would be shot onto an adjacent block, and pushed off with a piston. The arrow would then appear to float, even though it was actually glitched on top of the block it was originally shot onto. Then, the block beneath the glitched arrow would be broken and replaced by a redstone input. Different inputs had different effects on the metadata:
- String would +1 to the data value if it was originally an even number
- Wooden pressure plates would set the data value to 1, regardless of what it originally was
- Gold pressure plates would add the number of arrows inside the block to the data value
- Wooden buttons would always +8 to the data value
This worked because the arrow was attempting to update the metadata of the pressure plate, but had the wrong coordinates, so actually updated the metadata of another block, in this case, the piston.
In order to create a headless piston, the only useful one of these was the gold pressure plate. You could place the piston facing into the bedrock, shoot 8 arrows into it and then perform the glitch. This would always +8 to the data value of the piston, making it headless and not changing the direction. Because it used headless pistons, this method could break bedrock in any direction.
This glitch was patched in 1.7.6-pre 1, but it also worked in the 1.8 snapshots released before 14w17a.
Flaming Arrows and TNT EditThis worked by shooting a flaming arrow into a block and then letting it fall. While the arrow was still falling, a TNT block would be placed in the position of the original block. When the arrow landed, it would replace whatever it landed on with ignited TNT.
The arrow entity remembered the coordinates of the block it was last on. When it lands, it still thinks it's stuck in that block, and since the block is now TNT, and the arrow is on fire, the arrow creates a primedTNT entity.
Headless Pistons (1.0 to 1.2.3) Edit
Shortly before the release of 1.1, a forum user called Spanonediscovered the very first way of changing block metadata. Regular Hexahedron then used a variation of the machine to create headless pistons, which could, in turn, be used to destroy bedrock next to them.
Many different versions of the machine were made, and it was possible to break bedrock in all directions using it because it used headless pistons. The simplest method to break through the nether ceiling was showcased by JL2579 in one of his server tours.
When the redstone torch was broken by the liquid, the piston was instantly pushed into its place. The piston's metadata was then replaced by that of the liquid, changing it to a headless piston.
Mushrooms (Beta 1.8 pre-release only) Edit
Giant mushrooms were first introduced in Beta 1.8 pre release, and, for a short time before the official release, could be used to break bedrock. Mushrooms could be placed on any block and then have bone meal used on them to create a giant mushroom. The block the mushroom was placed on would be replaced with dirt, no matter what it was before.
This could only break bedrock from above, and required enough space for the mushroom to grow. This meant it could not be used to break through the nether roof, but could be used to dig through the bedrock at the bottom of the nether and the overworld, including y-0 bedrock.
In the Beta 1.8 full release, this was fixed by only letting giant mushrooms grow if the mushroom was placed on dirt.
Hoes (up to Alpha 1.2.6) Edit
In Alpha, dirt could be tilled even if there was a block above it. Bedrock could be broken by placing dirt beneath it, tilling it and then placing a seed on the farmland. The seed would replace the bedrock block. This was removed in Beta 1.0 because dirt could not be tilled if there was a block above it.
This method broke the bedrock from below, requiring at least 1 block of space beneath the bedrock. This meant it could be used to break through the nether roof, but could only break a small amount of bedrock at the bottom of the world.