How long would it take? short of covering your world completly in dungeon brick, granite and marble it's impossible. Even if you wipe out all corruption/crimson pre-hardmode and by some chance you kill the wall of flesh in a spot where the game will try and place the corruption/crimson and hallow(since they always spawn in a V pattern starting from where the wall was slain) but is filled with unturnable blocks you will still get that stuff spreading. Since in order to get the first three hardmode ores in your world you have to smash demon/crim altars and doing so spawns random patches of corruption/crimson and hallow somewhere in your world, the more you smash the more new ores you spawn and more corruption/crimson and hallow you seed..

Okay the summonable flying piggy bank has got to be the greatest addition to this game ever. That little item has save me so many headaches it's not funny. Pack too full of crap and I really don't want to warp back to base yet? Summon the piggy! About to take on a boss and don't want to lose my fat stacks of coins I am currently hauling around? Summon the piggy. Seriously why has it taken till 1.3 to give us this thing?

Also fuck the hardmode events.. I swear the game just does things out of spite. Get done battling a boss and am low on pots and buffs? well here have a solar eclipse, followed by a full moon bloodmoon and a mechanical boss spawn and then top it off with a good ol pirate invasion the next morning.. "can't let you have that breather so you can craft some more health pots and buff potions, as well as buy more ammo or finally craft that higher tier gear you desperately need.

Oh and btw your nurse and gun dealer are dead, have fun!"

Seriously that happened to me three days in a row..

At least those damn clowns can't blow up your base anymore like they did in 1.1 nor can wraiths just start spawning in your house. That was a nightmare, every damn bloodmoon I would be taking care of the wraiths swarming in and boom there goes half my base because three or four clowns decided to bomb their way in from the top since I had a lava pit traps lined with dungeon brick at both main entrances which in turn were "sealed" with active stone block in my old 1.1 base which in turn was buried in the side of a man made mountain. It was a massacre.. so many NPC's lost their lives that day and it took at least a hour to rebuild.

How? o.o

I put rain clouds in the house. You can cut them off of clouds with a pickax.

Oh, I knew about the clouds, I thought maybe you'd somehow made it rain permanently. :D
Still, that's neat, especially the fact that the chandelier is still lit. Logic!

In that case, I need to change my after shave ;p

I had the King Slime appear whilst I was building an arena right next to my building, which is almost spot on centre.

Also sheesh! It was my first boss & wow, Expert mode is tough, it`s great, in a masochistic sort of way ;)

The Slime Rain event wasn't in the game, that post was made pre-1.3 which introduced it. During that event King Slime will spawn once enough other slimes have been killed, regardless of where the player is.

So, can you get the King Slime to spawn in the Underworld?

What happens if the King Slime falls into lava?

o.0? If all else fails.

Oh far out! Thanks! :D

as crackpot pointed out just use the slime crown, if you have trouble finding rubies just gather some slush, desert fossil and silt blocks and feed them into the extractinator and your bound to get some along with some cash as well.

or just wait till the slime rain even happens and slaughter slimes till he spawns.

Looks like I'm holding off on anything until tomorrow. I wish they'd stop updating the damn thing!

It takes damage. You can test this by bringing lava to the surface using buckets and then spawning it.

Also, official patch notes for 1.3.0.6 while those not on Steam waits for it: http://forums.terraria.org/index.php?threads/terraria-1-3-0-6-is-live.27035/