How to get more steel?

You can get steel from the Explorer's Cabin. Regularly claim your free rewards and complete more explorations to get more steel.

A great thing about exploration is that you can set it to battle automatically, and it will keep going until you get to an opponent you cannot defeat.

Steel is essential for upgrades, so make sure you do as many explorations as you can in order to get the most steel.

Believe me, at the start you cannot get enough, and you'll probably find that you are spending it all virtually as soon as you get it.