What is CryptoKitties? A Beginner’s Guide on the Blockchain Collectible Cats
Last December, a new game became a trending fad in the blockchain world. Collectible CryptoKitties allowed users to buy, own, and trade unique, adorable cartoon cats on the blockchain. Around the time of launch, CryptoKitties was so successful that it slowed the Ethereum network. Just a few days after launch, users had already spent over $1 million on these collectible cats.
The cool thing about CryptoKitties is they’re a demonstration. Of course, they’re fun and cute on their own. However, they also show the potential of blockchain for trading and securing digital assets. This was the driving principle behind the creation of CryptoKitties. In the white paper, the founders discuss the narrow focus of most blockchain projects on payments. Ultimately, they hoped CryptoKitties would help people expand their vision of what a blockchain could do.
Not a Currency, But an Asset
Most blockchain projects launch with a cryptocurrency. These are tradable tokens that represent some utility value in a project or even a share in a company. Token offerings have become an incredibly successful fundraising device for new startups. In some cases, too successful as projects with minimal expertise or roadmap can raise millions of dollars.
CryptoKitties are not a currency. Instead, they’re blockchain assets. They’re structured similarly to most other tokens. However, they have one major difference. Each CryptoKitty is unique, and they’re not meant to be fungible. Fungibility is key for a currency. It means that a dollar is a dollar, no matter where you got it, what year it was minted, or where it has been before you received it. They have value because we agree on their value.
Non-fungible tokens rely on their uniqueness and scarcity to create value. Each CryptoKitty is an ERC-721 token with unique features. These unique features are written into code as the CryptoKitty’s phenotype and genotype. In other words, the CryptoKitty’s genetic information that determines its appearance and other characteristics is written directly into the code of the ERC-721 token.
The phenotype and genotype combinations mean that there are four billion possible CryptoKitties, making it likely that the CryptoKitty you own is unique in the world.
Built on Ethereum
The game uses the Ethereum network rather than creating its own blockchain. Smart contracts administer every aspect of CryptoKitty creation and trading. As a result, there’s no central authority that can change, remove, or otherwise alter a CryptoKitty once it has been created. The person who owns that ERC-721 token owns the kitty, and can hold it, allow it to mate, or trade it at any time.
Since it’s built on Ethereum, CryptoKitties uses Ether as payment for all transactions. It’s not yet possible to buy CryptoKitties with fiat currency. In the future, the development team hopes to offer options for fiat payment.
Owning and trading CryptoKitties also requires you use a browser integration for your Ethereum wallet. MetaMask is the easiest option to do this. It is possible to write code that communicates directly with the CryptoKitty smart contract. However, to use the online user interface and view your kitties, you’ll need to install MetaMask and keep the CryptoKitty tokens in that wallet.
Where New Kitties Come From
The genesis cat was born and adopted on December 2, 2017. Since then, a new cat has been born every 15 minutes. This will continue until November 2018, at which point no new generation zero CryptoKitties will exist. According to the white pa-purr (yes, that’s the real title of the document), only 50,000 gen-0 kitties will ever exist.
Outside of the generation zero cats, CryptoKitties can also breed with each other. Any kitty can be a sire or a dame for a breeding pair. The owner of the dame will receive the newly-born CryptoKitty. That kitty will have the genetic cattributes (yes, that’s also not a typo) of its parents, but it will also have random variations in some cattributes as well. Those random mutations might be rarer than its parent cattributes. In very rare cases, a “fancy cat” with custom artwork might be born.
There’s no theoretical limit to how many CryptoKitties can exist. As long as you’re willing to pay the transaction fees for breeding two cats, you can create a new one.
A market for breeding rare cattributes has emerged over time. If you’d like to breed your CryptoKitty with another person’s kitty, you’ll likely need to pay a siring fee to that owner. There’s also now a market for “virgin” kitties that have never been bred before, especially gen-0 virgins.
This explosion in digital collectibles and unique assets raises the question: Is this art?
Cryptokitties are beautiful and cute. Nevertheless, they also resemble art in that they’re unique and valuable because they’re scarce. This is especially true in the case of fancy cats that come with custom artwork and are even rarer.
Blockchain art and digital scarcity is an emerging trend. It’s possible to imagine artists using the blockchain to secure the authenticity and provenance of their pieces. CryptoKitties just happens to be blockchain-native. However, that doesn’t mean it’s not art.
Ultimately, the creators of CryptoKitties call it a game, and they don’t seem interested in the artistic aspect. Instead, the company behind the project feels it’s a fun way to help people learn about blockchain. Just the same way Minesweeper introduced people to computers, Flash games showed people the internet, Farmville brought people to social media, and Angry Birds taught people about smartphones.
Technical Stuff: The CryptoKitty Smart Contract
CryptoKitties relies on a modular structure of a core contract plus other smart contract libraries. The core contract tracks ownership and ownership transfer for all kitties. It also checks approval for siring new CryptoKitties. Beyond that, all other functionality comes from pointers in the main contract that call other contracts in the library.
Breeding, genetics, and auctions take place in other contracts. As previously mentioned, all functionality is available to anyone by interacting directly with the smart contracts on the Ethereum blockchain. However, for most users, it’s easiest to use MetaMask and CryptoKitties’ intuitive online user interface.
How to Buy CryptoKitties
The easiest way to get a CryptoKitty is to purchase one at auction on the website. Since kitties can have unique characteristics, each will sell for a different price.
Next, get the MetaMask browser extension and set up a MetaMask wallet. Transfer your ETH to your MetaMask wallet. Then, follow the prompts on the CryptoKitties website to sign up and bid for a kitty.
How to Store CryptoKitties
You can keep your CryptoKitties in your MetaMask wallet if you want to be able to view and trade them in the browser.
If you’d like to put your kitties in cold storage, a Ledger Nano S can store ERC-721 tokens.
Team: Axiom Zen
The team behind CryptoKitties is Axiom Zen. They create all kinds of projects on the cutting edge of technology like virtual reality and blockchain. CryptoKitties is only one of their ventures.
The funding stream for CryptoKitties is unique in the blockchain space. Axiom Zen is selling the generation-zero kitties at auction and keeping the proceeds. However, they also make a small percentage (3.75%) on every transaction that takes place in the official marketplace. After this year, all generation-zero kitties will be gone and ongoing revenue will come from transactions in the marketplace.
That doesn’t mean that using the marketplace is required. You can negotiate and trade CryptoKitties outside the official marketplace without paying Axiom Zen a cent. The auction smart contract is merely a useful and trusted option to transact.
Timeline & Roadmap
In the first week after its launch in December 2017, the platform had over 60k users, 100k cats, and $5 million in sales. That week, CryptoKitties accounted for 25% of Ethereum network traffic.
The following week, it grew to 150k users and over $15 million in sales.
In 2018, a CryptoKitties mobile app will launch with some of the functionality of the full web version. The project also aims to accept fiat currencies this year. By the end of 2018, all generation-zero cats will have been born.
Whether you think CryptoKitties is a fad, the fact remains it has been effective at introducing people to blockchain and widening the possibilities of what blockchain could be used for beyond currency. As one of the most successful blockchain projects in terms of news coverage and mass adoption, CryptoKitties has played an important role in the history of blockchain. That alone should make CryptoKitties a valuable collector’s item many years from now, even if the market for such collectibles dies down over the coming years.
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