The Nether



"Explore a scary new realm! A brand new hell world for fast travel. Portal in, move ten meters, portal out, and you’re hundreds of meters away."

- The Halloween Update promo poster

The Nether is a molten hell-like dimension filled with fire, lava, and dangerous mobs.

Accessing


To access the Nether, the player must construct a nether portal in the Overworld (portals created in The End do not activate). To create the portal, the player must first build a rectangular obsidian frame, ranging in size from a minimum of 4×5 to a maximum of 23×23. Once the frame is built, it can then be activated by placing fire within the frame, using flint and steel, fire charge, dispensers or any materials.

An activated portal allows most entities (with the exception of the wither, the ender dragon, and entities riding or being ridden by another entity) to be transported to a corresponding portal in the Nether. In Survival, the player must stand in a nether portal for 4 seconds to get to the Nether. The player can step out of a portal before it completes its animation to abort the teleport. The portal generates a sound effect while the player is inside it. If there is no corresponding portal, a new 4×5 portal is created. The portal can be destroyed by breaking the obsidian frame, by a nearby explosion, or by placing water or lava into it with a bucket or dispenser. Any of the blocks in the corners can be destroyed without destroying the portal.

In the Old world type, it is impossible to construct a Nether portal. The portal block must be placed using cheats.

Environment
Bedrock comprises the top (below layer 127) and bottom 4 layers in a rough pattern. In the infinite worlds of the Java and Bedrock Editions, the Nether is also horizontally infinite. $$, the build limit in the nether is 128 blocks, despite it being 256 in all other dimensions.

Glowstone clusters generate on ceilings, and mushrooms grow abundantly on the ground. There are patches of floating gravel and soul sand. Small caverns form in the netherrack, which contain random nether quartz and nether gold deposits. Near the level of the lava oceans, patches of magma blocks generate within the netherrack, making travel difficult and potentially damaging to armor.

Nether fortresses, the Nether's only naturally occurring structures, provide valuable loot, and are the only places where blazes and wither skeletons naturally spawn. Nether fortresses are also the only places where nether wart naturally generates.

The Nether has no day-night cycle and no weather. Natural sources of light include fire, lava, portals, and glowstone. Even with a light level of 0, the Nether has a dim ambient light (roughly equivalent to light level 8 in the Overworld). Light otherwise functions exactly the same as it does in the Overworld and the End.

Locations in the Nether correlate to Overworld coordinates, but horizontal Overworld distances are scaled down by a ratio of 8:1 for travel in the Nether. Therefore, traveling one block in the Nether means traveling eight blocks in the Overworld. For example, in a perfect scenario, a player who enters a portal in the Overworld at x=0, z=0 and travels in the Nether to x=1000, z=1000 returns to the Overworld at x=8000, z=8000. This makes portals a useful tool for traveling long distances in the Overworld.



Most items and blocks in the Nether function the same as they do in the Overworld, with a few notable exceptions:


 * Beds explode and cause fires when a player attempts to sleep in one. It has an explosion power of 5. The explosion is larger than that of TNT, which has an explosion power of 4.
 * There is no way to place liquid water in the Nether without the use of commands, besides the usage of a cauldron.
 * Using water buckets produces steam particles and a hissing sound, leaving the player with an empty bucket.
 * Ice that is melted or smashed in the Nether does not produce water.
 * If somehow placed using cheats, water takes on a reddish-brown color.
 * If placed from a water bucket into a cauldron, water takes on a reddish-brown color.
 * A wet sponge instantly becomes a regular sponge when placed.
 * Lava flows twice as far (8 blocks) and much faster in the Nether than in the Overworld.
 * Grass blocks and leaves take a dead-looking brownish color since the Nether is a warm biome.
 * Maps generate a brown-gray static pattern. The player's direction indicator spins randomly; its location is still relative to the player's location in the Nether, except in the New Nintendo 3DS Edition, where it is always in the center of the map.
 * Clocks spin wildly, making it impossible to tell the time while in the Nether. Compasses also spin wildly unless connected to a Lodestone, which they then point towards.
 * Snow golems rapidly take fire damage and die, due to the Nether being a warm biome. However, they can survive if they have the status effect.

Mobs
The Nether is home to its own share of mobs, most of which are fire- and lava-proof. Skeletons, chickens, and endermen are the only Overworld mobs that can naturally spawn in the Nether; $$, baby zombie pigmen may spawn as chicken jockeys.

Other Overworld mobs do not naturally spawn in the Nether but can be teleported through portals (with the exception of withers and ender dragons).

Biomes
There are currently five biomes in the Nether(four in Bedrock).

Nether Wastes
The first of these largely consists of large platforms of Netherrack, as well as massive lava oceans. Lava sources hidden in the Netherrack are also common, making mining somewhat dangerous. Random fires across the Netherrack are yet another hazard to the unwary player. Zombie Pigmen and Piglins both spawn commonly. Soul Sand and magma occasionally appear in large clusters, as well as veins of Nether Quartz. Nether Gold Ore spawns with half the rarity of quartz. The fog is a dark red color. With the night vision effect, it becomes a light shade of red.

Crimson Forest and Warped Forest
There are two types of "forest" biomes that can be found in the Nether, both the Crimson Forest and the Warped Forest. Both biomes are made up of huge fungus structures that are composed of wart blocks, shroomlights, and stem blocks. The ground is made out of nylium and netherrack, with fungi, roots and other vegetation growing on the nylium. Most blocks and vegatation have equivalents in both biomes:
 * Crimson Forest: Crimson fungi, crimson nylium, crimson roots, nether wart blocks, weeping vines, crimson stems, crimson Planks, crimson hyphae, and other blocks made from crimson planks.
 * Hoglins only spawn in this biome.
 * Piglins spawn more frequently in this biome than the Nether Wastes.
 * The fog color in the crimson forest is a deep red color, similar to the color found in the Nether Wastes biome.


 * Warped Forest: Warped fungi, warped nylium, warped roots, warped wart blocks, twisting vines, warped stems, warped planks, warped hyphae, and other blocks made from warped planks.
 * Nether sprouts can only be found in this biome and do not have a crimson forest equivalent.
 * Endermen spawn much more frequently in this biome when compared to the rest of the Nether.
 * The fog color found in the warped forest is a dark blue color, which turns into a magenta color when viewed with the night vision effect.

Soul Sand Valley
This biome has a high spawn rate of both Ghasts and Skeletons. Large pillars of Basalt also spawn. The biome itself is covered in Soul Sand, Soul Soil, and Soul Fire. Nether Fossils also generate here, which differ from the Fossils found in the Overworld. The fog in this biome is a cyan color similar to soul fire.

Basalt Deltas
This is a volcanic-themed biome containing large mountains of basalt and occasional patches of blackstone. There are ash particles everywhere and the fog is a dark grey color. The night vision status effect turns the fog white. Magma cubes spawn commonly in this biome, as well as ghasts and striders. Nether gold ore and ancient debris cannot be found here.

Respawn Anchor
A respawn anchor is a block that can be used to set the player's spawn point within the Nether, similar to beds in the Overworld. Usage of the respawn anchor in either the Overworld or The End results in an explosion, destroying the block.

Generation
Within the Nether, mobs such as Ghasts, packs of Zombified Piglins, and the occasional Magma Cube and Enderman spawn. Certain structures, such as Nether Gold Ore, Nether Quartz Ore, Glowstone veins, and Nether Fortresses generate only in the Nether. The Nether is also the only place where Ancient Debris, a material used in making Netherite Scrap and later, Netherite items, can be found.

While Water cannot be placed in the Nether dimension, Ice can and water lakes (and other Overworld structures) can still generate, if the Nether is used in a superflat or buffet preset.

Naturally generated
Naturally generated blocks includes those that are created through the world seed.

Naturally created
Naturally created blocks are created through a combination of events that lead these blocks to be placed by natural causes, not by the player.

Structures
These blocks are generated as part of nether fortresses, but only when the "generated structures" option is on.

Generation in Bedrock Edition
In Bedrock Edition, if the nether is used as the biome for overworld generation, a bedrock ceiling generates at altitude 128. If a river generates in the nether biome, the bedrock ceiling does not generate over the river biome (which exposes sunlight). The terrain consists entirely of stone, without any netherrack or nether related block generated. Although the terrain is entirely stone, no ore is generated (including dirt, gravel, andesite, etc). Caverns and lakes (with red-colored water) still generate. The player is still able to place water in an overworld nether biome, but trying to sleep in a bed still causes an explosion.

, when Overworld biomes generated in the Nether dimension, at layer 30, the lava sea is replaced with water sea. Passive mobs cannot spawn, while monsters can. Overworld structures cannot generate, but nether fortresses still generate. Nether mobs such as zombified piglins and magma cubes can spawn only as part of the fortress. Overworld mineral veins still generate as normal, but no Nether vein mineral generates. Despite lava springs being the only light source, the lighting is reasonable, as players can still see without light sources. The fog is the same as sky color in the overworld. No trees generate, and only some vegetation such as kelp, seagrass, flowers, grass, fern, sugar cane, cactus, and mushroom can generate in sparse quantities, and disks are also rare. Additionally, the Nether music track is exclusive to this dimension.

Folder
$$, the Nether is stored in. Deleting this file resets the Nether, so that all player-made changes and buildings in that dimension are undone.

$$, the  folder contains several collections of chunks. Some of these files are used for the Nether, but it is impossible to tell which ones simply by reading the file name.

Advancements
There is a whole tab dedicated to the Nether in the advancement system, all involving visiting the Nether in some way in order to advance.

Trivia

 * Upon entering the Nether as a single player, the passage of time freezes in the Overworld, resuming when the player returns unless the command is used. This is due to the spawn chunks no longer being ticked, and not chunks loading and unloading as some players believe. The spawn chunks are kept loaded when there are no players in the overworld, but most stuff other than basic redstone stops working.
 * 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. Although it is confirmed that the 3 dimensions are not supposed to be stacked vertically.
 * $$, if a section of the bedrock ceiling is removed (e.g., through commands) mobs cannot spawn directly below where the ceiling should be because Nether mobs except skeleton can only spawn underground. (cannot spawn on surface)