VoxoDeus Integrates Chainlink VRF to Power NFT Mints and the Omega Key Game

6 min readJun 22, 2022


A provably fair and publicly verifiable source of randomness

We’re excited to announce that VoxoDeus — an interactive, 3D NFT collection — has integrated Chainlink Verifiable Random Function (VRF) on Ethereum mainnet. By integrating the industry-leading decentralized oracle network, we were able to access a tamper-proof and auditable source of randomness needed to help mint Voxos NFTs and distribute keys for our Omega Key Game in a provably fair manner. VRF created a more exciting and transparent user experience, as users could independently audit the source of randomness used to help distribute rare NFTs and keys.

Say you walked into a casino, sat down at a slot machine, and yanked the one-armed bandit. House edge aside, there are two things that’ll make the game fair. First, it shouldn’t matter who you are or where and when you’re playing — your chances of winning should be equal to that of the next person. Second, you shouldn’t have to trust blindly that the casino’s proprietors are playing fair. So a game of chance is only fair when it’s both random and there’s a means of verifying that it is. In the case of slot machines, there are algorithms to generate randomness and gambling authorities to ensure that their spin is fair.

But how is this problem solved on the blockchain? Blockchains have neither a built-in source of randomness or an independent authority to verify randomness on the player’s behalf. This is where Chainlink Verifiable Random Function (VRF) helps provide a verifiable and provably fair source of randomness.

The cause that needed a hero

When we launched VoxoDeus, the world’s first large-scale 3D-interactive NFT, one of our USPs was that we’d be returning a portion of the ETH collected to the community as a reward. The distribution of this reward would be gamified, to give every VoxoDeus owner a shot at winning.

In February 2022, VoxoDeus minted all 6312 Voxos NFTs, which unlocked the Omega Key Game. The Omega Key Game was a strategic trading game where players collected keys to win ETH rewards. The game lasted 17 days, from February 22 to March 8, and saw hundreds of players fiercely trade and compete for big rewards from a pool of 250 ETH. To claim rewards, players had to obtain the Voxos that possessed keys and then register them “on-chain” via voxodeus.io once they’d accumulated the required amount.

VoxoDeus released 8 stunning keys to kick off the game. One or more keys were released daily thereafter. A total of 24 keys had been released by the time all rewards were claimed upon which the Omega Key Game ended. It was critical that we used a provably fair and verifiable source of randomness to distribute these keys.

Creating randomness in computers has always been hard because computers are designed to be deterministic. Blockchains are also deterministic, making it similarly difficult to generate a reliable source of randomness on-chain. Thankfully, Chainlink — — the industry-standard decentralized oracle network — — provides a verifiable and tamper-proof RNG service known as Chainlink VRF.

We chose to integrate the industry-leading Chainlink VRF because it’s based on cutting-edge academic research, supported by a time-tested oracle network, and secured through the generation and on-chain verification of cryptographic proofs that prove the integrity of each random number supplied to smart contracts.

So how did Chainlink VRF play its heroic part?

Chainlink VRF helped ensure that the NFT mint and keys distribution was provably fair and verifiably random by providing proofs of the random numbers’ integrity on-chain. The solution gave our community confidence and peace of mind that every user had a fair chance of receiving an NFT or key, and that they hadn’t been pre-assigned — no one could obtain information that would give them an unfair advantage, including anyone from VoxoDeus.

Chainlink VRF works by combining block data that is still unknown when the request is made with the oracle node’s pre-committed private key to generate both a random number and a cryptographic proof. The Omega Key Game and Voxos NFT minting smart contracts will only accept the random number input if it has a valid cryptographic proof, and the cryptographic proof can only be generated if the VRF process is tamper-proof. This provided our users with automated and verifiable assurances directly on-chain that the key and NFT distribution process was provably fair and was not tampered with by the oracle, outside entities, or the VoxoDeus team.

Integrating Chainlink VRF was necessary for VoxoDeus to help show Voxos NFT holders and Omega Key Game players that all NFTs and keys would be assigned to users impartially; — with uniform probability across all eligible participants.

So how did VoxoDeus use Chainlink VRF in the Omega Key Game?

VoxoDeus created publicly-available smart contracts that randomly selected Voxos to be assigned Omega Keys. Random keys were released by running the smart contract, which leveraged Chainlink VRF to obtain a random number that determined which user would receive a key. Each Voxo that was selected was announced on the VoxoDeus discord in a dedicated channel.

Because the “random selection” smart contract was made public, every stage of the key selection process was transparent and verifiable on-chain, including the random number sourced from Chainlink VRF - — ultimately helping prove that all keys were distributed in a provably fair manner.

“Chainlink VRF helped ensure all keys in our Omega Key Game, as well as the Voxos NFT minting process, used a provably fair and tamper-proof source of randomness. This helped give a new level of transparency for the VoxoDeus community and inspired confidence in the integrity of the underlying games that drew them to our project in the first place.” — Sotiris, CEO of VoxoDeus

About Chainlink

Chainlink is the industry standard for building, accessing, and selling oracle services needed to power hybrid smart contracts on any blockchain. Chainlink oracle networks provide smart contracts with a way to reliably connect to any external API and leverage secure off-chain computations for enabling feature-rich applications. Chainlink currently secures tens of billions of dollars across DeFi, insurance, gaming, and other major industries, and offers global enterprises and leading data providers a universal gateway to all blockchains.

Learn more about Chainlink by visiting chain.link or reading the developer documentation at docs.chain.link. To discuss an integration, reach out to an expert.

About VoxoDeus

VoxoDeus is the next evolution of NFTs, introducing the world’s first large-scale 3D-interactive collectible NFT that is ready for the metaverse. We created VoxoDeus with the idea of bringing the most value for holders, while creating something stunning and everlasting. A project steeped in lore with 6,312 total Voxos, spread across different species, traits, factions, and rarity levels. Each Voxo comes beautifully presented with a bespoke background scene and accompanying soundtrack offering a truly immersive experience.

Join VoxoDeus on Discord, and follow us on Twitter (@voxodeus) and Instagram (@voxodeus) for updates.




The group behind VoxoDeus — The first Interactive 3D NFT collectibles from the Cypherverse. :: Voxelated. Techno-utopic. Pretty good design.