Magma in Minecraft- Lava it and Leava It

Lava serves a secondary purpose in Minecraft besides being fatal, an ore magnet, and a useful resource to gather in buckets.  Lava is your method for creating not only an infinite amount of cobblestone, but also for getting to the Nether.

When lava flow blocks are exposed to water, the water cools them- and turns them into blocks of cobblestone.  Because of this, with a few buckets and a little ingenuity, you can actually create for yourself a small blocky generator whose sole purpose is to make an infinite amount of cobblestone blocks.  While this doesn’t seem like much with the sheer amount of stone present in the world, the amount of time and trouble it can save you from digging out huge tracts of the underground is something you simply cannot afford to overlook- especially if you’re making cobblestone roads, a stone castle, and other sorts of structure from the ubiquitous rocks.

This in itself is already plenty useful, given that stone can also be formed into steps and slabs- but even more important is reaching the Nether.  The Nether is essentially the second of three major steps in Minecraft, the third and final of which is reaching the End.  This underground world of hellish heat, lava lakes, horrifying creatures, and dark netherstone is where you will find your advanced resources in the hands (or bodies) of monsters- resources you need to reach your greatest power and to brew magical potions.

There are only two ways to reach the Nether, though- find a Nether portal, or make a Nether portal.  Finding a Nether portal is a long and hard process involving huge amounts of underground exploration.  Making a Nether portal, though, only requires obsidian- and obsidian requires lava.

While a lava flow touched by water will become a block of cobblestone, a lava source block touched by water is forever destroyed- by being turned into a block of obsidian.  Obsidian is simply the hardest material available in the game- and while you cannot build tools out of it, it can be used for anything else a block can be used for- and to make Nether portals.  However, Obsidian being so hard is an immense drawback- because it means that the dark stone can only be gathered with a diamond pick.

Diamond being rare and occurring only in tiny pockets means that diamond picks are usually in short supply- and are just about the most important thing you can make with the resources you can get in the World.  While other picks can destroy obsidian blocks, they cannot gather them- and breaking the block takes huge amounts of time.  Even an iron pick takes a good part of a minute to break through an obsidian block.  While it can be difficult to craft obsidian walls without accidentally turning them into Nether portals, the sheer durability can be well worth it- even an exploding Creeper generally won’t break through obsidian.  It is this- the forming of obsidian- that makes lava most vital in the game.

Never underestimate the effect of the ability to dump lava into a dangerous trap, though....