In Gold & Goblins, cards are used to upgrade jewels in mineshafts and unlock automation.
They come in different rarities, and each rarity has its own purpose.

Gray Cards (Common)

• These are common cards.

• They have lower profit multipliers and provide basic upgrades.

• Many early mines require gray cards to level up a jewel and activate automation.

Green Cards (Uncommon)

• These are uncommon cards.

• They give higher profit multipliers compared to gray cards.

• In some mines, only green cards can be used to unlock automation or reach required upgrade levels.

This system ensures that each mine remains a unique puzzle and encourages collecting all card types.