Merge

Two cards of one element and tier become one card a tier up with one more star. The higher id burns.

Merge two cards of the same element and the same tier. The lower id survives one tier up, with one more star than the better of the two. The higher id is burned and the supply drops by one. You can chain it, tier 2 into 3 into 4, all the way to tier 9.

Before this page Tiers and stars are on Sealed cards, reveal and traits. Weight is on Decks and weight.

What it is #

mergeCards(keepId, burnId) is the only way a card changes after mint. Tier doubles a card's weight, so two equal cards merged are weight-neutral on the tier leg. The extra star is the net gain, 25% of base. The trade is a distinct design: the deck loses one, and set bonuses count designs.

Rules #

• keepId < burnId, else MergeOrder. The lower id always survives.
• You must own both. Approvals do not count.
• Neither card may be in a deck, else CardLocked.
• One-of-ones cannot merge, else UniqueNotMergeable.
• Same element, same current tier, tier below 9, else ElementMismatch, TierMismatch, MaxTier.
• Result: tier + 1; stars = min(6, max of the two + 1); element, design and edition unchanged.
• Merging is open only after reveal. It cannot be paused.
• The card's image follows its tier, so the art changes with the merge, and MetadataUpdate(id) tells marketplaces to refresh.

Numbers #

Worked example #

Fire ids 3,277 and 3,301 both reveal as tier 2, with 1 and 3 stars.

mergeCards(3277, 3301)   3,277 becomes T3 with min(6, max(1, 3) + 1) = 4 stars
                         3,301 is burned; totalSupply drops by 1
weight before            2 x 1.25 + 2 x 1.75 = 6.0
weight after             4 x 2.0 = 8.0                              (MinersNFT.sol:336-344)
mergeCards(3301, 3277)   reverts MergeOrder                          (MinersNFT.sol:317)

Edge cases #

• A previously merged card counts at its new tier. T3 from a merge pairs with a minted T3.
• Merging two copies of one design keeps the design count of your deck intact; merging two different designs loses one.
• Burned ids are never reused. The collection only shrinks.

Verify it on-chain #

• cardTraits(id) returns the effective tier and stars, merges included.
• totalSupply() falls by one per merge; ownerOf(burnId) reverts afterwards.

Not in the game #

• "Stars are upgrades earned after minting". Cards mint with 0 to 6 stars; merge is the only upgrade.

Next #

Where the money goes and what the team can change.