ERC-1155

ERC-1155 is often called the "multi-token" standard because a single deployed smart contract can track balances for an unlimited number of distinct token types, each identified by its own token ID, rather than requiring a separate contract per asset the way ERC-20 and ERC-721 do.

Proposed in June 2018 by Enjin co-founder Witek Radomski and several co-authors, the standard was designed for blockchain games that needed to manage in-game currency, crafting materials, and one-of-a-kind items within a single economy. Each token ID can behave as fungible (a supply of thousands, like a stack of arrows), non-fungible (a supply of one, like a rare sword), or semi-fungible (a fixed limited edition), all inside the same contract.

The standard's signature feature is batch operations: functions such as safeBatchTransferFrom and batch balance queries let a wallet move or check dozens of token types in one transaction instead of many, cutting gas costs and simplifying approvals through a single "approve all" permission. Because every transfer is a "safe" transfer, receiving contracts must confirm they can handle the token or the transaction reverts, reducing the risk of assets getting stuck in a contract that cannot use them.

Marketplaces such as OpenSea adopted ERC-1155 early for gaming collections, and it now underpins many NFT collections, event tickets, and loyalty tokens, where efficiency across many items matters more than the strict one-owner-per-token design of ERC-721.