User:MasterShizzle/Hellstone Mining Sandbox

Hellstone Mining Guide: Trial Draft

Overview
Mining Hellstone is a dangerous and sometimes tedious process but worth it, as most of the highest-tier items in the game require large amounts of Hellstone bars. Hellstone is a valuable trade item for multiplayer as well.

This guide takes you through it, step by step, to hopefully get you all the hellstone you'll ever need.

Preparation
Hellstone mining requires the following: The following aren't required, but will make the job much easier: In addition, you're going to want the best armor and weapon you can lay your hands on. If you've already gained access to the dungeon then there are great weapons there, and Shadow Armor is easily obtainable by this point. This guide assumes that you're familiar with the methods discussed in Guide:Mining Techniques.
 * A Nightmare Pickaxe or better
 * A Hellforge, to smelt the ore into bars
 * Obsidian in large amounts, 1 for every 3 hellstone ore
 * An Obsidian Skull: Hellstone will damage you on contact without it, much like Meteorite. You'll need lots of Obsidian to forge all those Hellstone bars, so be sure to get an extra 20 to craft a skull.
 * Healing Potions, the more the better
 * A Magic Mirror: Great when used as a "panic button".
 * Dirt or Stone: You'll need plenty of stable building material for tunneling through Lava pools, and both dirt and stone are easy to find. Later on you'll have piles upon piles of Ash to backfill and create your tunnels, so bring only enough to get you through until then.

The Trip Down
The first step is to create a quick means of entry into the Underworld. The quickest method is using a drop shaft, which is explained in more detail in Guide:Mining Techniques. It's nigh impossible to get all the hellstone you'll ever need in one trip, so count on making multiple trips down. A drop shaft is the quickest way there, but remember that water evaporates in the Underworld so you need some other means of negating fall damage at the bottom.

Avoiding Lava
The Underworld has more lava than any other area in the game, and deposits are both larger and more frequent than average. Combining lava with the collapsing nature of ash makes for very hazardous tunneling, so shore up your tunnels and step lightly where lava is involved.

Lava deaths are extremely common this far down, no matter how careful you may be. Any coins you lose while submerged in lava can't be recovered, and the loss adds up quickly. Stash your coins before heading down.

Using an Obsidian Skin Potion negates lava damage and will give you a second shot at life if you fall in. Add in a Gills Potion and you can safely mine in lava without coming to the surface, which will protect you from lava slimes and hellbats. Imps can still shoot through lava, and bone serpents and demons can both survive in it, so you'll still have enemies to deal with.

Dealing with Monsters
Never try to mine Hellstone from the surface of the Underworld, as you'll soon be overwhelmed with enemies and won't be able to devote any time to mining. Instead, tunnel below or make a quick shelter around yourself to keep unwanted baddies out. The monsters of the underworld are tougher and more aggressive than in any other area in Terraria, and mining Hellstone throws you right into their backyard. If you're getting overwhelmed with enemies and don't want to waste a lot of potions while fighting them off, using a Magic Mirror to teleport back to your base will reset the spawns and give you a fresh start. Just make sure you've got a means to get back down quickly.

Fire Imps are the biggest headache, as their attacks penetrate walls and they respawn quickly after being killed. One way to avoid their attacks is to simply get them on one side of the screen and ignore them: if you're mining constantly, your pickaxe should deflect most of the fireballs and you can mine relatively unhindered. Imps need a clear space 4 blocks high by 3 blocks wide to spawn, so make your tunnels as small as possible if you want to avoid them entirely.

Bone Serpents are hard to dodge in confined spaces, but it can be done. If your armor is decent you may wish to simply take the hits and use potions, as it tends to be quicker. The longer you spend fighting these things the more other enemies can get in the way, so beware. Their spawn rate is so low that once you kill one you don't have to worry about another one for a good while.

Demons, lava slimes, and hellbats can show up as well, but are much easier to deal with when mining in a confined space. If you're below the Underworld surface most of the time and keep away from open spaces these shouldn't bother you.

Using an Artificial Meteor Biome
If you don't feel like dealing with the Underworld spawns at all, grab 50 pieces of Meteorite Ore and place them in close proximity to one another, preferably in an easily-built rectangle. This will create an artificial Meteor Biome, replacing all the creatures you normally encounter with Meteor Heads, which are more predictable and more easily dealt with than Underworld spawns. Mine all around you and take all the Hellstone you wish, taking care to keep your Meteorite on-screen, then move the deposit to a new location.

If you have 100 or more pieces of Meteorite and feel like being especially "safe" you can leapfrog two (or more) deposits in a horizontal direction. Place one deposit of 50 blocks to establish the biome, mine all the Hellstone you can see, then place the other 50 Meteorite in a block just offscreen and recover the first. Mine the hellstone in the new biome, place another deposit, and repeat. In this way you can mine yourself silly without ever seeing an Underworld creature.

See Meteorite for more tips on surviving in the Meteor biome.

Dealing with Empty Space
Spawns will only appear if there is an empty space for them, except for Bone Serpents.

Mining the Hellstone
Hellstone deposits are easier, as Hellstone is a stable material. Make a safe tunnel to the deposit with the techniques described above, then mine out all the ore except the topmost block in each column (to prevent a cave-in). Either leave the topmost ores behind or mine them out as you leave. Backfilling with extra ash will prevent Fire Imp spawns.

Keep in mind that hellstone is immune to explosives, so your pickaxe is the only way to get it. Bombs and dynamite can still be used to clear away large amounts of ash, especially when using a Meteor Biome

Forging the Bars
A Hellforge is necessary to make use of the hellstone you get. Hellforges are in nearly every building in the Underworld and require a Meteor Hamaxe or better to harvest directly. If you don't have a sufficiently powerful hammer, just destroy one of the bricks the forge is resting on. This will destroy both the brick and the forge. Hellforges are not immune to lava, so make sure the forge you get is high and dry.

Required Amounts
The following table shows all the items that use Hellstone Bars and the amounts of Hellstone/Obsidian to make them.

In total you need about 6 1/2 stacks of Hellstone and just over 2 stacks of Obsidian, assuming that you're making just one copy of everything.

That's quite a pile of ore, not to mention all the work that will go into getting full Gold Armor and an enchanted Boomerang, plus beating Skeletron to snag a handgun. Whether you mine it all at once or split it into smaller chunks is up to you.