- Main article: Nether Portal
A Nether portal is made by creating a 4x5 (2x3 on the inside) or larger door frame out of obsidian and then lighting the inside of the frame on fire with flint and steel or a fire charge. The corners of the frame may be left out, using only 10 obsidian as opposed to the usual 14. When one stands 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.
A portal can be shut down if part of the obsidian frame or the portal block inside is removed (not including corners), or the portal itself gets caught in the radius of an explosion (including those caused by a ghast's fireball).
When re-entering the Overworld, any distance covered in the Nether is multiplied by 8, effectively making the Nether a fast-travel zone that allows greater distances to be covered in a short amount of time in the Overworld.
A useful way to save obsidian is to create a Nether portal without the corners as they are not required for a Nether portal to function.
- Ghast ― A flying, jellyfish-like, 4-block-cubed-sized monster which shoots fireballs and emits its trademark whispers and screams.
Ghasts can be damaged by any conventional weapons, but they do not get hurt when on fire. A ghast can fly into lava falls or lava lakes, but even if they burn, they don't get damaged (As of the November 10th Update). The fireballs they shoot can be deflected back at them using a fist or any tool by hitting it just before impact, killing it instantly if it hits (shooting an arrow or using the fishing rod on the fireballs works too). This unlocks the achievement Return to Sender. They drop gunpowder and ghast tears. Ghast fireballs cannot destroy cobblestone. For this reason, many players like to use cobblestone as protection. Ghast fireballs can destroy Nether portals.
- Skeleton - a hostile mob that shoots arrows and drops 0-2 bones, 0-2 arrows, armor (if equipped), and/or a bow (most likely used, however, there is a small chance a bow may be enchanted).
Skeletons can be one of the most difficult hostile mobs to combat. Because of their ranged weapon, skeletons are difficult to combat. Skeletons are best taken out with a bow, a shield and, if available, a strong sword. Because skeletons drop arrows, it is suggested to use the bow in this situation. Additionally, skeletons can't shoot through vines, but a player can. Skeletons should be fought by strafing (moving back and forth) and close quarters combat when a bow or crossbow is not available.
- Soul sand - A brown block. When walked on, it slows the movement speed of a player and mobs that walk across it and makes them sink slightly, as soul sand is only 7/8 the size of other blocks. It can be used to create minecart-only passageways and docks, as well as one-way doors. Its slowing effect is doubled if an Ice block is placed under it. Some pixel-souls can be seen on this block. Soul fire can be lit on this block.
- Soul soil - A brown block similar to soul sand and is only found in the soul sand valley biome. It does not slow down players nor mobs, and fire lit on it becomes blue soul fire.
- Bone block - A white block which makes up Nether fossils, and can be commonly found throughout the biome. They may generate as one of four different variants of the skull or one of four different variants of the spine, and ribs and ribcages can be found in fourteen different variants.
- This biome spawns skeletons, ghasts, and endermen.
- In snapshot 20w16a players will now see bastion remnants in all biomes except in the basalt deltas.
- Most people say that this is the hardest Nether biome to be in.