ERC-1155: A new standard for The Sandbox

The Sandbox
The Sandbox
Published in
4 min readJun 11, 2019


The use of the latest blockchain technologies on The Sandbox

ERC-1155 is a new standard for representing virtual items on the Ethereum blockchain that allows the creation of multiple types of tokens in the same contract. It is particularly useful for items used in games, many of which will come in numbers. In The Sandbox, a user-generated content platform that utilizes blockchain technology, it allows Creators to mint any number of copies of the same Items/Assets.

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The team of The Sandbox, represented by its Lead Blockchain Architect Ronan Sandford, is one of the main contributors helping make ERC-1155 a new standard, along with the teams of Enjin and Horizon Games.

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There are several benefits to the ERC-1155 approach in comparison to other token standards like ERC-20 and ERC-721. It allows developers to consolidate the logic in one contract and build an ecosystem around one single address. It also allows batch transfers to operate in the confines of the same contract — and all of this can be accomplished at a reduced gas cost.

ERC-1155 was started almost a year ago by Witek Radomski from Enjin. At Pixowl, we quickly realized we needed something similar, but we wanted a standard that would be compatible with ERC-721. After looking at a few options, we decided ERC-1155 was the best way forward and helped Enjin and Horizon Games fine tune the standard with a special focus on ERC-721 compatibility.

This feature is important for us, as we want our creators to be able to create both NFTs (via ERC-721) that can work with the existing ecosystem and fungible tokens (via ERC-1155) that offer them the ability to mint a collection of items they can sell for use in various gaming experiences.

ERC-1155 allows anyone to mint any number of copies of their game item

This means that an ERC-1155 token with a supply of 1 can be also seen as an ERC-721 with a specific owner. We can thus operate on them via ERC-1155 batch transfer, as well as getting all the interoperability benefits of ERC-721.

However, we took this idea even further. Our current implementation allows owners of ERC-1155 tokens (with supply > 1) to transform them into ERC-721. This reduces the supply of the original ERC-1155 token by one while giving the newly minted token the capacity to be personalized like any other NFT.

This has interesting use cases, such as the ability for a creator to create a collection that will trustlessly generate NFTs at the point of purchase. This in turn gives the buyer the possibility to prove he or she was the first to get an item from a collection.

The Sandbox will allow Game Creators to utilize ERC-1155 tokens in their games

Another important requirement for us was the ability to provide true ownership guarantee to our users without costing too much gas. While many blockchain games provide only ownership of a number to save on gas, we provide a proof of ownership of the asset’s data itself (graphical representation and any other other properties attached to it) by storing its hash in the smart contract while the data itself resides on IPFS. And thanks to the design of ERC-1155, our latest implementation allows creators to mint more than 1,500 types of assets at once in one block.

The journey to make ERC-1155 a new standard was not easy, but we are very happy with the result. Special thanks to Enjin for bringing the ERC-1155 into existence and thanks to Andrew Cooke, Philippe Castonguay and all others involved!

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Multiple Copies of the same Assets isn’t an issue with ERC-1155!