how do I upgrade my castle to use Mithril?

You buy all of you lowlands and save up 4 billion and tap you castle then upgrade

 

Get 25 lands, then upgrade the castle as you would any other building.
Lvl 2: 4 billion cost, requires all 25 lowlands.
Lvl 3: 10 billion cost, requires 12 highlands explored.

 

Your* thats three times i've done that today :?
Noob-adopt-master, beat this noobiness out of me

 

You dont need a level 2 castle to use mith though.

 

You don't need a lvl 2 castle to use mithril, but you do need it to buy mithril

 

No you don't

 

You need the castle code.... Swabia has it

 

I hope you know that you can get banned for this. It is breaking the ToU. Just saying. Hope for the best...