The Nether



The Nether, also referred to as "The Nexus" in Notch's Blog on Tumblr and was previously known as Hell and The Slip, is a different dimension existing in Minecraft worlds, first existing in Minecraft Alpha version 1.2.0 on October 31st, 2010 (The Minecraft Halloween Update).

Accessible via a Portal, it can be used for travelling large distances on the above ground map quickly. The Nether also contains Block types not seen anywhere else, as well as supplies of Block types found on the normal world, like Mushrooms, Gravel and Lava. The Nether is home to four Mobs: Ghasts, Magma Cubes, Blazes, and Zombie Pigmen. All of these mobs are only found in the nether with the exception of Zombie Pigmen which spawn in the overworld when a pig is struck by lightning.

The Nether functions as a second map in a player's Minecraft World. When it is entered, the chunks from the above ground map are unloaded and the Nether chunks begin to load. Terrain generates infinitely here just like on the above ground map. If the player dies in the Nether, their items will stay there while the player respawns in the overworld.

Terrain
The Nether's terrain is largely composed of netherrack, which is arranged into large, smooth outcroppings and niches; it is essentially a cave. There are patches of gravel and soul sand, as well as stalactites of glowstone hanging from the ceiling. Mushrooms grow abundantly in the Nether, and natural fires are a common sight. Small tunnels form in the netherrack, which contain no ores or hidden caverns. Nether fortresses can be found as well. These Nether fortresses are made up of nether brick, Nether Brick Stairs, nether brick fences and crops of nether wart. At the very bottom, beneath an ocean of lava, is a layer of Netherrack and bedrock. The very top of the Nether is similarly bedrock.

Navigating the Nether can be very dangerous. The strange, dimly lit landscape conceals pits and sudden cliffs. Many lava streams flow from the ceilings, down the netherrack and into a lava ocean. If one dies near this lava or a patch of fire, it is a safe assumption that some of one's items will fall in and be burned.

The sky and fog in the Nether are dull dark red. Thunderstorms can cause the shade to flicker quickly, a known bug.

Environment
The Nether has no day/night cycle and no weather. The only natural sources of light are fire, lava, and glowstone. A dim ambient light can be seen throughout the Nether, but this is purely a visual effect and does not affect game mechanics. Contrary to some common myths, light works the same way in the Nether as it does in the Overworld: there are 16 levels of brightness and one level falls off for every transparent block it radiates through.

The Nether does have one special property relating to light: plants that usually require it, such as flowers and Nether Wart, can survive in complete darkness when planted in the Nether. However, due to a bug, this doesn't work below natural veins of glowstone or below lava source blocks that appear naturally in cave walls. Plants at any level below these formations, even if separated by other terrain, will uproot if not adequately lit.

Blocks and Structures
Entries marked with a D require additional data to fully define the block in a Beta world. Entries marked with a T have tile entities associated with them to store additional data. Items with IDs in red cannot be legitimately obtained in the player's inventory in the game; they can only be obtained by "hacking" (such as the use of Inventory editors) or, in multi player using the /give server command. Items available only in Creative mode are in blue.

Naturally Generated
Naturally Generated includes blocks that are created through the world seed.

Naturally Created
Naturally Created means a combination of events that cause a new block to be placed by natural causes, not the player.

Structures
Same as Naturally Generated, but these blocks will only be created with the "Generate Structures" option enabled. However, Nether Fortresses still generate even with "Generate Structures" set to "off", which may be a bug, or because the lack of Blazes, spawning only within the Monster Spawners in Nether Fortresses, renders the game unwinnable, and removing the ability to participate in brewing potions, as you need one blaze rod to make one potion brewing stand.

Nether-Affected Materials
When Grass blocks are obtained using a tool with the "Silk Touch" enchantment, such as a shovel, and taken into the Nether, it becomes possible to have grass in the nether. Using Water Buckets will only cause the water to sizzle and leave steam. This makes growing Sugar Cane impossible since the plant requires water to survive. Wheat farms are also affected by this. They can survive without water, although they will grow much more slowly.

Actual blocks of water can be placed in the Nether, but this requires Inventory Hacking or Map Editing. Blocks of Ice that have been hacked into the game, spawned via Creative Mode, or acquired through mods can be placed and broken to leave water blocks behind as well.

Trees will grow normally, and their leaves will take a dead-looking brownish color, like in Desert biomes. However, they grow in odd formations and occasionally morph shapes when they are altered. This makes Nether-trees useful for traps or endless log harvesting on occasion. Trees are also hard to keep in the Nether because of the substantial amount of lava, which ignites them.

It is always a good idea to bring paper down into the Nether, and then craft a map as getting lost is easy and happens frequently- Note you'l only see the location of where you are on the map, not the actual scenery, as you are inside a massive cave. Compasses and Clocks can be brought in freely, but they will not work correctly. As the Nether is in a totally different dimension from the Overworld, Compasses will be unable to find the original spawn point, and Clocks cannot determine the position of the sun. Their arrows and dials will instead spin and flail madly. Maps made on the above ground dimension wont show the player's position in the other dimension. For Maps to display the Nether, they must be Crafted there. Beds will explode when a player attempts to sleep in one. This can be a useful strategy to quickly mine materials in the Nether, but only if the difficulty is set to peaceful.

Lava flows twice as far in the Nether than in the Overworld (generally 8 blocks, instead of 4 blocks).

Mobs
The Nether is home to its own share of mobs.


 * Ghasts, huge jellyfish-like creatures, will lazily hover around. They are 4×4×4 blocks large, and have 9 tentacles hanging from them. If they spot the player, they will shoot fireballs at them, which can be deflected by shooting arrows at them, punching them or hitting them with any tool. The reflected fireballs will instantly kill the Ghast, if it is hit. These will explode and often leave craters, if the blast-site is weak enough. They make screeching and whimpering noises, something like a purring kitten or an angry baby, and can be heard for great distances.


 * Zombie Pigmen spawn in groups and wander aimlessly. They will not harm the player unless attacked. If they are, all the Pigmen within a 32 block radius rush the player, often causing ambushes from behind as the player attempts to attack while fleeing.


 * Blazes are able to float and shoot 3 fireballs at the player in a quick succession. They appear to catch fire just before shooting said fireballs, then "cool down" until they can shoot again.


 * Magma Cubes are spring-like mobs that slowly hop towards the player. If killed, they split into 2-3 smaller versions of the original one. Magma Cubes are occasionally rare.

Nether mobs are completely fire-proof and can often be seen wandering into lava, where it will take them a while to get out due to the slowdown it causes on movement.

Normal World Mobs like Pigs and Zombies will not spawn in the Nether. Chickens can be forced to spawn there if they hatch from a thrown Chicken Egg, however, but they will not spawn naturally afterward. Squid will spawn in large amounts in any hacked body of Water due to the fact that the water is the only suitable place in the whole map. Creative mode Spawn Eggs still work normally in the Nether.

Portals and Fast Travel


Nether Portals are made by creating a 4x5 (2x3 on inside) door frame out of Obsidian and then lighting the inside of the frame on fire with Flint and Steel or a Ghast's fireball. When you stand inside the portal for the first time, it will create a portal in its equivalent area of The Nether. A loading screen will appear during the change of worlds.

If you create a portal in the Nether and re-enter the normal world, any distance covered in The Nether is multiplied by 8, effectively making The Nether a fast travel zone that allows for greater distances to be covered in a short amount of time in the normal world. Linking a network of portals between the Nether and the Overworld can be tricky though. See the Nether Portal page for the precise details of how this can be done.

Due to Ghasts, it is recommended that players enclose their portals with a blast-resistant material (Cobblestone is cheap and effective). This will prevent Ghasts from being able to hit the portal and shut it down. Optionally, the player can choose to carry a Flint and Steel with them in case this happens, or just trick a Ghast into shooting the portal again, therefore effectively re-activating the portal.

It is not possible to get to the Nether via The End.

History


The Nether was one of the key features to be added in the Minecraft Halloween Update, and was announced on October 4th, 2010. This announcement stated that there would be a "hell world" that could be used for fast travel. It hinted it would utilize Portals and that distance travelled inside the would be multiplied greatly on the map above ground. On October 10, a screenshot was released by Notch depicting what the Nether would look like. With the rest of the Halloween Update's features, the Nether was released on October 30.

In the original announcement, Notch mentioned "a brand new Hell world." When the preview was sent out on 29 October 2010 to a couple of gaming websites, the new dimension was called the Slip to avoid offending religions and to have a more original name. It was referred to as 'The Nexus' on his personal blog. It was finally changed to “the Nether” on the day of the Halloween update release.

Along with the Nether, Ghasts, Zombie Pigmen, Netherrack, Soul Sand, Glowstone and Portals were added. On November 10th, Lava was made to flow farther than it did on the Overworld.

There was a glitch where The Nether was a Biome. This was fixed in an unknown update.

In Beta 1.6, Portals were made to function properly in multi player, allowing players in servers to warp between the Overworld and the Nether. 1.6 also fixed a bug where the player could have menus open while inside Portals. When warping, the text on screen would appear totally grey.

In Beta 1.6.2 Beds in the Nether were made to explode if used. This can be used as a mining technique.

With the "Silk Touch" enchantment in the 1.9 pre-release 4, it was possible to legitimately obtain grass and water using ice in the Nether. Because passive mobs and squids will spawn in the only place available, it was possible to use this to control the spawning, which allowed the player to make highly efficient passive mob grinder, something extremely difficult to do in the overworld since animals stopped despawning in 1.8. The ability to pick up ice blocks with the enchantment was removed in a later version. Water also made Nether mob grinders easier as it can transport items without burning them as well as drown Nether mobs that are immune to lava, such as magma cubes and zombie pigmen.

In Minecraft 1.0.0, many new things were added to the Nether:
 * Magma Cubes
 * Blazes and Blaze spawners
 * Nether Fortresses and the blocks they are made of
 * Nether Wart
 * Ghast Tears dropped by Ghasts

File save location
The Nether is saved in the same way normal worlds are, but instead of mixing the world files inside the save folder, the files for Nether are stored in %appdata%/.minecraft/saves/Worldname/DIM-1 (on Windows), whereas normal world files in %appdata%/.minecraft/saves/Worldname. Note that DIM-1 does not contain its own level.dat, as the same level.dat in the upper folder is used for both Overworld and Nether. This means that even if a player changes the level data in the /world folder for a particular save, Nether portals will still take the player to the Nether world originally generated for that save.

Bugs/Glitches
An example of this can be seen here. 
 * On SMP, although extremely rare, The Nether and the Overworld may merge together while generating new chunks.
 * Placing Ice in The Nether near lava will cause it to melt, and create water that will not evaporate instantly.
 * Dropped items, if not blown up or burned, never despawn in the Nether.
 * Fire can sometimes be found in the base of a Nether Fortress's support, having replaced the Nether Brick block.
 * On extremely rare occasions in SSP, when going back to the Overworld from the Nether, Minecraft may crash. Upon logging back into the world, you are in an area far from the Portal in the Overworld, all of the items in your inventory are lost.
 * Zombies can rarely spawn in the Nether in SSP.
 * Due to the new 'Anvil' world type in 12w07b, the Nether extends beyond the top Bedrock barrier, allowing Mobs and Mushrooms to live above the ceiling. In Survival mode the only way to get to them is to stand just below the bedrock, use pistons to shove yourself into the Netherrack, then disconnect from the game, and reconnect. On reconnect, you will be spawned in the next free space above, which is above the bedrock.  The "Limbo" area above the Nether is an extremely efficient place to travel since there are no pigmen to block rails, or netherrack to block Enderpearl teleportation.  A less reusable, but simpler, method of glitching up is to drop gravel on yourself.

Trivia

 * The Bedrock ceiling of the Nether created a rumor that the Nether is underneath the Bedrock barrier on the above ground map. This is supported due to the fact that one of Minecraft's merchandise is a shirt that has the Nether below a Cavern, presumably below Bedrock level. This has been dismissed as creative mode / hacking let players get above the Bedrock to find the Nether's Void. Notch has said that the Nether and the above ground map are in entirely different dimensions.
 * When you warp from worlds, the direction you are facing is maintained (e.g., if you are facing east in the Overworld when you warp to the Nether, you will still be facing east).
 * While inside the Nether, furnaces will stop smelting and plants will stop growing/decaying in the Overworld. However, the day/night cycle continues and all the Mobs present are maintained.
 * Gravel is the only block found in the nether that is also found in the overworld (with the exclusion of obsidian and bedrock). Strangely, flint can still be mined from gravel found naturally in the nether. This makes no sense, as flint is a fossil and so needs water to form, and water cannot exist in the nether.
 * The idea for the Nether came from a transportation method used in the novel series The Wheel of Time by Robert Jordan. Within this transportation system, the Ways, you could travel a massive amount of distance in a few days instead of weeks. Like the Nether, the Ways has many dangers. Notch also once said that Jake, his co-worker, was a big key to the Nether. It isn't clear what exactly what that means.
 * One of the Level Themes in Indev was Hell. It was a normal map, but with a Lava ocean, perpetually dim lighting, and a black sky with dull red clouds.
 * If you stand on soul sand with lava at the same level adjacent to the soul sand, you will take damage if you step near the edges of the soul sand.
 * In SMP, if you disconnect and someone places blocks where you were, when you log in, you will spawn on top of the blocks. If there isn't any room above the blocks, you can spawn above the bedrock layer and you will be trapped. You can also do this to yourself by dropping sand or gravel on yourself.
 * There may be some areas where the ocean/lake of lava may go under an overhang and the lava will not illuminate that area. Going in there and creating light (placing a torch, lighting a fire, etc.) will fix this.
 * In 1.8 Creative Mode, you can break through the Nether's bedrock ceiling and into a red void. However, you will not take damage and you can explore the theoretical "cap of the Nether."
 * Pointing at entities (Minecart, Painting, etc.) in the Nether causes your inventory to become 'brighter'.
 * There is no naturally spawning Passive mob that has been announced in the Nether as of now, but chickens can be brought over.
 * Due to the mobs in the nether being fire proof, zombie pig men have been seen swimming up lava streams.
 * With no light sources around, the nether seems to stay at one light level, proved when being in a cavern with (no torches, glowstone, etc.,) the light level stays the same as outside.
 * A Superflat map will not make the nether flat.
 * Adding grass (Inventory editing or silk touch tool) and a spawner (Inventory editing) will allow you to spawn passive animals in the nether.
 * Nether actually means "Underworld" or beneath.
 * In the minecraft 1.2 pre release, all worlds heights have been double so it is possible to build in the void of the nether.
 * In Minecraft 1.2, pressing F3 to view the current biome will show "Hell"