So inviting! So annoying to get rid of if you make it wrong!!
Now you step through it. The screen starts swirling purple. The game takes a minute or two to create the Nether, your heart rate slowly increasing. Suddenly, the purple swirling reappears! You see a land filled with lava, the ground is made of steak or something much like it...
...and a floating jellyfish opens its eyes, the ground explodes, and you fall into the lava ocean below.
Lava is always there for you, typically directly below a diamond ore vein.
Now what? Well, you lost the results of two weeks of diamond mining, but you are eager to go back. Why? Because it's Minecraft, the game where danger is the most fun. Obviously.
So. Why did random stuff explode? Because you met a Ghast.
Now with extra firebombing!
What's that? It's obviously a large, floating jellyfish that shoots flaming snowballs. Duh.
Their fireballs are 50% as effective as a TNT block, but since the ground is made up of one of the worst TNT-resisting materials in the entire game (cobblestone will resist their weak fireballs with a resistance of 30. Dirt will be completely obliterated with a resistance of 2.5. Netherrack, the meatblocks that form the Nether, has a resistance of 2.), you don't need anything more powerful to fall to your death in the lava oceans below.
Oh, and they fly ju-u-ust out of your bow's range. Luckily, you can use your fishing rod to pull them towards you, then give them a serving of justice in the form of a sword. They only have 5 health (despite being huge), so it won't take very long to kill them. The only problem is that where there's one, there's usually 15 more.
Oh, and they all shoot at the same time. Good luck.
Once you're done running away from Ghasts as the ground behind you is bombed to oblivion, make a shelter out of cobblestone. This will resist the explosions. Now you just have to worry about Zombie Pigmen.
Do you see that sword? Now multiply that by five, all attacking you at once.
Zombie Pigmen are angry pigmen with swords. They spawn in crowds, and they knock off a quarter of your health on the lowest difficulty. Fortunately, they posess no malice towards you and won't attack you. Unfortunately, this means that if you were to accidentally throw a snowball at one, it will immediately summon its horde and they will stab you until you die. Also, if a Ghast hurts one, they will look for the nearest entity. If you're it, they will immediately blame you. Because, you know, people shoot exploding fireballs.
I'VE BEEN FRAMED!!
The only good thing in the Nether is glowstone, the most low-reward block in the game. It grows in the ceiling. This means that if you don't die of fall damage, you'll fall into lava if you aren't careful.
It's a huge pain to get. If you break that entire formation, you might get 3 blocks if you're lucky.
Breaking one glowstone block gives you one glowstone dust. Nine glowstone dusts can be assembled into one block. This block drops one glowstone dust. This means that for every nine glowstone blocks found in the Nether, you will get one placable glowstone block. And if you don't like where you put it, you'll lose the block. Use torches like a normal person for lighting, instead.