The Nether



The Nether (also known as "the Nexus" in Notch's blog, and previously, Hell or the Slip) is a hell-like dimension accessible only by entering a Nether Portal from the Overworld. It is home to several hazards, including fire, widespread standing and flowing lava, and Nether-exclusive mobs, items, and blocks.

Locations in The Nether correlate to Overworld coordinates, but horizontal Nether distances are scaled down by a ratio of 8:1. Therefore, traveling one block in the Nether means traveling eight blocks in the Overworld. This fact can be used as an Overworld travel shortcut, though the Nether is significantly more hazardous, with more complex terrain, making navigation difficult.

The Nether functions as a second map in a player's world. When it is entered, the chunks from the Overworld map are unloaded and the Nether chunks load instead. Terrain generates infinitely in the Nether just like in the Overworld. If the player dies in the Nether, they will respawn in the Overworld; any surviving inventory items will remain in the Nether.

Environment
Nether terrain is largely composed of netherrack that forms complex platforms and niches, with frequent lava pools, "lavafalls", and streams, and a lava ocean at its floor; it is essentially a complex cave that is hazardous and horizontally infinite. Lava also flows more quickly in the Nether. Bedrock comprises the very top and bottom layers, unlike the Overworld, which has no upper bedrock layer. Glowstone clusters hang from ceilings, and mushrooms grow abundantly on the ground. There are patches of gravel and soul sand, as well as random fires, which are another common Nether hazard. Small tunnels form in the netherrack, which contain random nether quartz deposits, but there are no hidden caverns to explore as in the Overworld.

Zombie pigmen are common, and ghasts can also spawn in any 5×5×5 area. Nether fortresses, the Nether's only naturally occurring structures, are where the rest of the Nether mobs spawn (like the blaze). These can provide important dropped items, but present some hazards. Nether Fortresses are also the only place where nether wart can be found.

The Nether has no day/night cycle and no weather. The only natural sources of light are fire, lava, portals, and glowstone. A dim ambient light can be seen throughout the Nether, and is what light level 0 looks like. Plants that usually require a minimum light level, such as flowers and nether wart, can survive in the Nether at light level 0. 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. Light otherwise functions similarly to the Overworld: There are 16 levels of brightness; the brightness granted by a light source is reduced by one level with every transparent block it radiates through; and each light source casts the same luminance as it would cast in the Overworld.



In the console edition, world sizes are limited to 862×862 blocks. In the Overworld, the edge of a map generates an ocean and (mostly) smooth shores, whereas in the Nether this limit is formed by a wall of bedrock that abruptly cuts off the terrain. These bedrock walls aren't smooth at all, as they seem to be generated in the same way as the bedrock located at the bottom and top layers of the Nether.

Nether-affected materials
There is no way to place water in the Nether in a Survival game, besides the usage of a cauldron. Using water buckets will produce steam and an empty bucket. Ice that is melted or smashed in the Nether will also not produce water.

Trees grow normally, and their leaves take a dead-looking brownish color like in warm biomes.

Maps only show a brown-gray static pattern. The player's direction will be spinning randomly, although its location is still relative to the players location in the Nether. For maps to display the Nether, they must be activated there.

Compasses and clocks arrows and dials will spin and flail madly.

Beds will explode when a player attempts to sleep in one. The explosion is larger than that of TNT, and creates fires.

Lava flows twice as far, and much faster, in the Nether as it does in the Overworld (generally 8 blocks, instead of 4 blocks).

Building snow golems will only cause them to melt, due to the Nether being a warm biome.

Portals


Nether portals are made by creating a frame out of obsidian and then lighting the inside of the frame on fire with flint and steel or a fire charge (fire charges can be launched at the portal frame with dispensers to activate it, preferably right next to it, allowing automatic ignition). The minimum requirement to make a portal is 10 obsidian blocks (4×5 to 2×3 portal frame). When the portal has been lit, a purple mist, as shown in the picture, appears inside it which can be selected by looking at it but not mined. It can be destroyed by mining an obsidian block next to it with a diamond pickaxe, a nearby explosion or placing water or lava into it through a bucket or dispenser. Also, the mist can be mined in creative mode and, interestingly creates the same noise made when glass is mined. Doing this turns off the nether portal but does not give the player a block of nether portal purple mist. When the player stands inside the portal for the first time, it will create a portal in its equivalent area of The Nether and transport the player to the Nether. A loading screen will appear during the change of worlds.

File save location
The Nether is saved in the same way normal worlds are, in the following locations by default:

Windows:

%appdata%\.minecraft\saves\worldname\DIM-1

Mac:

~/Library/Application Support/minecraft/saves/worldname/DIM-1

''Note: This Library folder is not the one in Macintosh HD, but the one inside your home folder. The only way to access this is to go to the Go menu, and select Go To..., and type ~/Library.''

Linux:

~/.minecraft/saves/worldname/DIM-1

On all systems, be sure to replace "worldname" with the name of your world.

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 and vice versa.

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
These blocks are generated as part of nether fortresses. Even if the "Generate Structures" option is turned off, Nether fortresses are still created.

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


 * s, 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 (actually taken from C418's cat), and can be heard from great distances. Also, they can be killed by firing 2 arrows and hitting the ghast. If killed, they drop gunpowder and/or ghast tears, used in brewing.


 * spawn in groups and wander aimlessly. They will not harm the player unless attacked. If they are, all Pigmen within a 32 block radius become hostile, and will rush the player (sprinting speed) if they move within 16 blocks. This often causes ambushes from behind as the player attempts to attack while fleeing. If killed, they drop rotten flesh and sometimes a gold nugget, and even more rarely, a gold ingot. They may also drop their golden swords, which may have one or two low-level enchantments, commonly Sharpness and Knockback enchantments, though rarely Fire Aspect and even rarer, Looting, may be found. Other golden objects may also drop, like a helmet. There are also baby zombie pigmen, which have a 5% chance of spawning instead of a normal pigman and can move considerably faster than their adult counterparts.


 * s are found in Nether fortresses and are primarily spawned through monster spawners found inside the fortresses. They are able to float and shoot 3 fireballs at the player in quick succession. They appear to catch fire just before shooting fireballs, then "cool down" until they can shoot again. If killed, they drop Blaze rods.


 * s are spring-like mobs that are the Nether version of Slimes. If killed, they split into 2-3 smaller versions of the original one. Magma cubes are moderately rare. If killed, they drop magma cream, used in Brewing.


 * s are the Nether equivalent of skeletons and spawn in nether fortresses. Unlike skeletons, however, wither skeletons use stone swords and are over two blocks tall. When hit by a Wither Skeleton, the player may be inflicted with the "Wither" effect for a few seconds, darkening the health bar and further damaging the player. When killed, the mob may drop coal and bones, and very rarely drop a wither skeleton skull (probability: 0.025) and the stone sword. The skulls are the key items to creating the wither.


 * s rarely spawn in nether fortresses in place of wither skeletons. They are one of two mobs (the other being chickens, see below) that naturally spawn in the Nether that are not fireproof.


 * are extremely rare mobs that consist of a baby zombie Pigman riding a chicken. They have the same movement speeds as regular baby pigmen and are immune to fall damage like chickens. If the Pigman rider is killed then the chicken will remain, which will lay eggs as if it was in the Overworld. This makes it possible to obtain raw chicken, eggs and feathers from the Nether without returning to the Overworld.

Other Overworld mobs like pigs and zombies do not randomly spawn in the Nether, but they can wander or be shoved through a portal. Throwing eggs and constructing golems works as normal (however, snow golems will die from the heat). Spawn eggs work normally in the Nether.

The Nether Reactor
There is no Nether in Pocket Edition. There is however, a structure known as the Nether Reactor. It is built from 14 blocks of cobblestone, 4 blocks of gold and 1 nether reactor core. It can be seen here: http://www.twitch.tv/jbernhardsson/b/337680976. The alternate Nether is very different from the regular dimension available in the computer and Console Edition. The alternate Nether is just a Netherrack room, and items randomly drop. There are zombie pigmen, although they are hostile.

Trivia

 * 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, people 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 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.
 * Upon entering the Nether in singleplayer, the Overworld will essentially freeze, and resume when the player returns. This is due to chunks loading and unloading.
 * If the player stands on soul sand with lava at the same level adjacent to the soul sand, the player will take damage if he/she steps near the edges of the soul sand. This is due to soul sand being slightly lower in height than other blocks.
 * Pressing in the Nether will display the biome as "Hell".
 * In the Xbox 360 Edition and PlayStation 3 Edition:
 * There is a wall of bedrock surrounding the map to stop the player from crossing the map limit as shown here.
 * Everything in the Nether is renewable due to the fact the Nether can be restarted infinitely.
 * Water in the Nether instantly evaporates and disappears; placing water from a bucket would only make a hissing noise and steam.
 * It can, however, be placed by, and would act as it would in the Overworld.
 * The command can be used to place water in the Nether.
 * When you place a grass block, it will appear as a faded greenish-yellow color. The faded color also applies to the dirt block.
 * It is possible to complete the game (access the End) without ever entering the Nether.
 * The numbers for the 3 dimensions are: -1=The Nether, 0=The Overworld, 1=The End. This implies that the nether is the next dimension over from the Overworld in the "down" direction and The End is the next dimension over in the "up" direction.
 * Skeletons and chickens are the only Overworld mobs that can spawn in The Nether. Skeletons have a chance of spawning in nether fortresses, and baby zombie pigmen can spawn as chicken jockeys.