Gods Unchained: how the NFT card game and its marketplace work

Gods Unchained is a free-to-play trading card game in which cards earned through play can become NFTs that players trade without paying gas. This guide explains how Gods Unchained and its marketplace work on Immutable, and how to build a card-game NFT marketplace with the same design.

In Gods Unchained, players can play without buying anything, and the blockchain stays mostly hidden from players.

How Gods Unchained works

Immutable, which began as a game studio and now builds blockchain infrastructure for games, created Gods Unchained. A player builds a deck around a god, plays matches and rises in a ranked list, as in other digital card games, and the blockchain affects what a player owns.

• Core cards and tradable cards. Every player unlocks a base set of cards for free, and cards earned in play or bought in packs can become tradable NFTs.
• Quality tiers and fusing. Each card comes in a quality level: Meteorite, Shadow, Gold or Diamond. A player can fuse duplicate cards into one card of a higher quality, which removes the lower-quality cards from supply.
• GODS token. GODS is an ERC-20 token that the game uses for rewards, crafting and governance features.
• Gas-free trading. The cards live on Immutable's chain, and players do not pay gas to trade them.

Immutable X, Immutable Chain and the shared orderbook

Gods Unchained cards first lived on Immutable X, a StarkEx-based rollup that Immutable built with StarkWare. Immutable's documentation says Immutable X merged into Immutable Chain in early 2026. Immutable Chain, also called Immutable zkEVM, is an EVM-compatible chain that settles to Ethereum, and its native token is IMX. Players who log in with Immutable Passport can have their gas paid by the game.

The Gods Unchained marketplace is not one website. Immutable runs a shared orderbook, so every marketplace built on the orderbook shows the same listings and fills the same orders. Immutable's documentation describes the orderbook as follows:

• A seller lists for free by signing a message, and gas is paid only when an order is filled.
• Buyers can bid on one NFT, on any NFT in a collection, or on NFTs with given traits.
• Immutable charges a fixed 2% protocol fee on every trade.
• The NFT contract sets the creator royalty, and the orderbook enforces it through an operator allowlist.
• The marketplace where an order was created can add a maker fee, and the marketplace that fills it can add a taker fee.
• The buyer pays all fees, and the seller receives the price minus the fees.

Why Gods Unchained works better than many NFT games

• The game came first. Players can compete without spending money, so speculators are not the only users.
• The design removes cards. Fusing and crafting use up cards and balance the creation of new ones.
• Players do not see gas. They trade cards the way they would in any digital card game.
• Shared liquidity. Every marketplace on the orderbook can fill a listing, so each listing reaches more buyers.

Gods Unchained still faces the usual market pressures. Card prices fell with the wider NFT market, and the GODS price moves with crypto prices in general. A balance change to a card also changes its market value.

How to build a card-game NFT marketplace like Gods Unchained

Claiming earned cards

An earned card should first exist as a record in the game database. The server mints the NFT to the player's wallet only when the player chooses to make the card tradable, usually through a signed mint authorization that a contract checks. This design keeps gas out of gameplay, and most cards never touch the chain.

The signing key that authorizes mints can create valuable items, so an attacker who steals it can mint any number of rare cards. Keep the key in a hardware security module or a managed key service, limit how many mints it can sign, and alert on unusual mint volumes.

Ownership changes must also reach the game. When a player buys a card on the marketplace, the game must detect the new owner quickly and show the card in the player's collection and deck builder. Index transfers in near real time, and treat the chain as the record of ownership for tradable cards.

Design rules for a card-game marketplace

• Keep game data off-chain. Decks, matchmaking and ranks stay in the game backend, and only ownership and quality need to be on-chain.
• Publish a balance policy. Explain how you handle a weakened tradable card before players spend money.
• Review tournaments. Card-game communities form around competitive events, and paid entries with prizes need a legal review.
• Disclose pack odds. A pre-launch pack sale is a primary sale and needs published odds. The NFT launchpad development guide covers phased mints and fair randomness.

The NFT gaming platform guide covers the game side, and the Axie Infinity clone guide covers a creature-based economy and the ways it failed. Immutable's developer documentation describes its current SDKs and orderbook.

Effort

The card game is the large build, and a marketplace on top of a shared orderbook is small in comparison. On a chain with a shared orderbook, two or three engineers need two to three months to build a marketplace and a claiming flow for an existing card game. That figure is an estimate from the component list, not a quote. A new card game built from nothing takes years of game production.

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