Today, OpenSea is announcing a new type of tradable digital assets on the marketplace: ERC-1155 items. In short, these are like ERC-721 items, but they have different behavior and more flexibility, which we’ll explain below. It’s a new Ethereum token standard and a new type of dapp on OpenSea!

ERC-1155 items have been tradable on OpenSea for a while now (there are over 200,000 that you can find already), but today they get the full attention that they deserve. Let’s start with what’s new in 1155. Then we’ll explain how you can get started trading, which games are already supported (17 so far!), and how developers can make 1155-compliant dapps!

What is ERC-1155 and What’s New

The ERC-1155 token standard provides a way to make one smart contract govern almost an unlimited number of tokens — technically, 2²⁵⁶ token types with up to 2²⁵⁶ copies of each. Additionally, each token is semi-fungible. Unlike ERC-721 non-fungible tokens (NFTs), which can only be owned by one address each, semi-fungible means:

1. Each token type can be owned by multiple addresses
2. One address can own multiple copies of each token

This expands the design space for building game economies and provides efficiency benefits as well. ERC-1155 is a result of the combined efforts of multiple companies working together to achieve these two goals, including Enjin, Horizon Games, and The Sandbox.

What’s needed now is a marketplace for the (at the time of writing) 208,319 new semi-fungible assets on Ethereum! And that’s what’s here today:

How to Trade ERC-1155 Tokens on OpenSea

Check out your OpenSea account page to see which items you already own, or visit the supported collections on OpenSea (listed below) to buy one.

To sell an ERC-1155 item, it’s as simple as clicking Sell, and then specifying the total price and quantity you want to sell. If you specify an end date, the price will decline to the amount you want until the end date is reached, and then your listing will be automatically cancelled (expired) for free.

You only have to pay gas the first time do you sell an item (which may include approving the token for trading). If you want to sell for Enjin ENJ, Sandbox SAND, or another payment token, click the dropdown below and set your price:

Placing Offers

As with other tokens on OpenSea, you can place offers on 1155 items by clicking “Make an Offer” on the item’s page. Offers are non-binding, but because an item can have multiple owners now and any owner can accept it for you, many people will consider your offer at once!

ERC-1155 Games on OpenSea

Even before this official launch announcement, there are already 17 games on OpenSea using mainnet ERC-1155 contracts, and many are already ranked in the top fifteen dapps by volume. Special thanks to all of them for working with us to make a great marketplace experience.

You can also see these games with the “new” label on the OpenSea rankings page, ranked by weekly volume. Here are three examples:

Age of Rust Marketplace on OpenSea: Buy, sell, and explore digital assets

Year 4424: The search begins for new life on the other side of the galaxy. Explore abandoned space stations, mysterious caverns, and ruins on far away worlds in order to unlock puzzles and secrets! Beware the rogue machines!

Spirit Clash Marketplace on OpenSea: Buy, sell, and explore digital assets

Spirit Clash is a battle for supremacy. You must clash your way through the three spiritual cores of Mind, Body, and Soul to claim victory. The first player to control two of the cores wins the game, but your opponent won’t let you take them easily. Summon Followers that will clash for your Overlord.

The Six Dragons Marketplace on OpenSea: Buy, sell, and explore digital assets

Welcome to The Six Dragons, the first Open World RPG powered by Blockchain Technology. Discover 64km2 of Open-World full of surprises, escape 1 billion dungeons, craft items that you truly own and participate in a player-owned, decentralized economy with real-world value.

How to Create ERC-1155 NFTs on OpenSea

Updated Jan 13, 2021

If you’d like to quickly make ERC1155 items without coding or paying gas, read this blog post introducing our new Collection Manager.

Information for Developers

Interested in deploying an ERC-1155 contract on OpenSea? If you already have an 1155 contract on mainnet or the Rinkeby testnet, there’s a chance that OpenSea automatically discovered your items! You can also use the Get Listed flow to have OpenSea re-crawl the items and add them to the marketplace:

Don’t have a contract yet?

We can help you get started. Here’s a work-in-progress tutorial and codebase for creating your own ERC-1155 contract.

Contact us in the #developers channel on Discord or on Telegram! We’re very responsive 🙂

What’s Coming Next

Crowdsales, gas-free pre-sales, and whitelisted airdrops using ERC-1155! Stay tuned using any of the following channels, ranked by signal-to-noise ratio 😉

• The #announcements channel in our Discord
• Our e-mail newsletter
• Our Twitter account
• Our Telegram group