Thursday Lesson: Mineshaft Upgrades p.2

⛏️ Once your zombies open up the mineshaft, you'll see which card you need to automate it (common grey or uncommon green).

📈 And to increase the profit from a certain mineral mineshaft, you may level up the card of this particular mineral regardless of its rarity.

🟩 All you need is enough resources: Cards of this mineshaft and Essence (if you're short on any of these resources, they will be marked red)

⬆️ If the upgrade is ready for the mineshaft that is already operating, you will see an arrow sign over this mineshaft.

⏱️ And of course, you can upgrade your cards whenever you want — just check them in your Cards Tab.