Java Edition only
The world boundary is the area at the edge of the Minecraft world.
The boundary of the world has several "layers".
The first layer is the world border, which lies at X/Z ±29,999,984 by default, and establishes an arbitrary blockade to prevent the player from advancing. There are several methods of bypassing this border.
The second layer lies exactly one chunk further, at X/Z ±30,000,000. At this point, there is an invisible wall preventing the player from advancing, even in spectator mode. Using commands such as
/tp will not work, since the game will not accept any value beyond ±30,000,000. However, by using a minecart (in a superflat preset in which the top layer is rails), the player can reach even further, up to ±X/Z 30,000,496; at that point, the player is frozen in place until the minecart is killed, and then the player will be teleported back to the ±30,000,000 mark.
The third and final layer lies at X/Z ±30,000,496, which can be considered the absolute edge of the Minecraft world, as chunks will no longer generate beyond this point. It is impossible to advance past this point without the use of external modifications, as this value is hard-coded into the source code of the game.
The maximum possible height is 1.797×10308, the limit where mathematics break down in the game's code. If the player attempts to teleport beyond this limit, the game will read the number as infinity and refuse to teleport.
By editing the source code for the game, it is possible to extend the terrain generation and world border past X/Z: ±30,000,240 (up to X/Z: ±2,147,483,647) and function completely normal (no ghost chunks, mobs spawning). The game performs normally even at distances of X/Z: ±1,000,000,000, and the commands will accept values beyond the 30 million limit. However, at further distances, block lag begins to become noticeable and mob behavior begin to behave very strangely. Attempting to travel or load chunks near X/Z: ±2,147,483,647 will simply cause the game to automatically crash. Thus, it is advised one sets the world border several hundred blocks before this limit.
- Gravity-affected blocks (such as
gravel), while falling, will jitter in bizarre patterns for several seconds, but will ultimately land on the ground as normal.
lava will fall normally, albeit at a much slower pace due to long response times.
pistons may sometimes not render until they receive another block update.
- Flame and smoke particles from certain blocks, like
monster spawners and
end portals, only appear on the side facing away from the edge.
- Flame particles will still appear around the entire mob spawner block as a mob is spawning.
- Beyond the X/Z 30,000,000 mark:
Beyond this, most of the unintended behavior of blocks and entities is caused by the world border (as detailed here), rather than the massive distances of the boundary itself.
|?||Blocks beyond X/Z: 32,000,000 do not generate. If the player tries to walk over the edge, they will be glitched position forever.|
|v1.2.0||"Fake Chunks" (where chunks of bare terrain render, but physics do not function properly) now appears beyond X/Z 32,000,000 and they the blocks can now be fallen through.|
|1.8||The Far Lands phenomena was removed, as an unintended side effect of the large changes in the terrain generator.|
|The "fake chunks" now start at X/Z: 30,000,000 2 million meters less than in Alpha 1.2.0 - Beta 1.7.3.|
|1.0.0||?||Many lighting glitches and strange air pockets form on multiplayer, although untested in singleplayer.|
|1.7.2||13w36b||Minecraft crashes after X/Z: ±29,999,840 on Default, Large Biomes, and AMPLIFIED worlds.|
|13w37a||There is an invisible wall at X/Z: ±30,000,000 that goes up to Y: 2,147,483,647. Walking on this wall far enough will cause the game to crash.|
|All blocks (including air) within the invisible wall act as solid blocks. Because of this, if the player is moved outside the boundary via commands or external tools, they will be unable to move.|
|Beyond the invisible wall, if items are thrown, the falling animation will be very jittery. The thrown item will disappear upon contact with any block other than air.|
|Beyond X/Z: ±32,000,000, the player will be kicked out with an "Illegal Position" message.|
|Some mobs (e.g. slimes) try to go past the world border.|
|1.8||?||The invisible wall was replaced with a proper world border, removing a large portion of the effects of the world boundary.|
|Fake chunks beyond the world border will no longer render, instead giving way to the Void:|
|At X/Z: ±30,000,001, the game will freeze. Any players who attempt to go any further will be kicked by the server, with the message "Illegal Position". The only way to fix this is to move the player back through the use of external programs.|
|1.8.2||pre4||The game no longer kicks the player for attempting to teleport beyond the world border, nor does the game freeze. However, the generated world does appear to become increasingly barren towards X/Z: ±30,000,000, and dropped items begin to 'clump' together in certain places.|
|1.9||?||Teleporting past X/Z 30,000,000 is no longer possible; the player will always remain before 30,000,000, even when using external programs.|
|Chunks beyond X/Z 30,000,000 are now rendered again, until X/Z 30,000,240. Many of the issues surrounding block and item rendering have also disappeared; with this, the world boundary is now generally more stable. Also, the chunks beyond X/Z 30,000,000 are now solid and now can perfectly generate structures like villages, mineshafts and trees.|
Though the reason for the world boundary is still controversial, it may have to do with the way Minecraft generates and loads chunks in the game. When the game's terrain generates it's terrain, it uses something called 3D Perlin Noise. This is a noise map that shows how high or low Minecraft blocks will generate. When the game generates the terrain, it creates a noise map of all the terrain that cannot be interacted with at all. Then, Minecraft would load in the chunks after the basic frame was in place. When the game generates chunks out to X/Z: 30,000,000 then for some reason, the game cannot load chunks beyond this point. However, the terrain noise map has generated the terrain all the way out to X/Z: 2,147,483,647. So Minecraft still generates the terrain noise map, but not the blocks themselves. So what we get is empty terrain that has the textures for the terrain that should be there.
- Traveling from one edge of the world to the opposite edge by powered rail would take 35 days and 10 hours. Building the rails for such a trip would require enough iron and/or gold to fill over 723 double chests even when packed into blocks, as well as sticks made from enough wood to fill over 135 double chests (as log blocks, not as wood planks, and excluding the redstone torches). ( 53 stacks of logs would be required just to make enough chests to hold all the building materials for this rail track.) If already crafted, the rails required would fill 17,361 double chests. If you had to gather the materials to make all those rails, you'd wear out 14,404 diamond pickaxes and 300 diamond axes (on average, about 3,601 diamond pickaxes and 75 diamond axes, both enchanted with Unbreaking 3).
- There's also the obvious fact that even if one were to amass all these materials, actually laying said track would require the player to travel the entire distance through other means anyway.
- Then there's the obvious fact that you need redstone torches. A torch can optimally light 17 blocks, so 3,529,412 torches are required. That requires 55,148 sticks/redstone dusts, which requires 2042 large chests, which requires 128 stacks of log blocks to make the chests (which requires 3 large chests).
- It is possible to generate trees and vegetation beyond 30,000,000 by loading a version of Minecraft after 1.9, then load a few chunks beyond the world border. Then, close the world and load a version of Minecraft between Beta 1.8 - Release 1.6 and load the same world. If you travel to the world barrier, there will be a few chunks that will generate beyond 30,000,000 that have trees and grass.
- It is possible to even generate Far Lands chunks using this method. Load a world in release Beta 1.8 - Release 1.6 and teleport to X/Z: 30,000,000. Close the world before the fake chunks generate and load the world in Beta 1.7.3. The Far Lands chunks will load and then, you can load as many chunks as you want. They close the world and load it in newer version and you will have Far Lands chunks in the 30,000,000 block area.