Reminiscent of Tamagotchi and Pokémon, the wildly popular digital pets and creatures of the 1990s, CryptoKitties is a blockchain-based game where players can collect, trade and breed digital virtual cats. CryptoKitties was the first Ethereum-based game, and its popularity underscored many of the network’s scaling issues.

This digital cat-breeding blockchain game caused quite a bit of congestion on the Ethereum blockchain, peaking in 2020. However, the game’s creators were able to address these issues.

What is CryptoKitties?

Launched in 2017, CryptoKitties was built by Dapper Labs, the company that uses blockchain technology to bring nonfungible tokens (NFTs) and new forms of digital engagement to fans around the world. CryptoKitties is also considered one of the world’s first-ever blockchain games.

In the game, each one of the digital collectible cats possesses a unique genome that determines its physical traits. Cats can be bred to create new virtual kittens and unlock rare “cattributes” or in-game cat features.

Is CryptoKitties an NFT game? Yes, CryptoKitties are unique, one-of-a-kind assets backed by NFTs, making them rare and valuable. They were built on Ethereum using the ERC-721 token standard, which allowed for the creation of unique NFTs.

CryptoKitties can be sold and traded, and cats with rare traits can fetch high prices. The rarest CryptoKitty of all time is the genesis cat, aptly named “Genesis” because it was the very first CryptoKitty hatched by the game’s creators. Genesis was sold in 2017 for 246.926 Ether (ETH), or around $119,328 at the time of selling. Ether has since appreciated, and so has the genesis cat.

How does CryptoKitties work?

Blockchain technology remains at the core of this game, but the unique CryptoKitties gameplay can be credited to its Genetic Algorithm (GA). The GA aims to mimic real genetic principles by structuring the smart contract code of each kitten like the DNA of actual living creatures.

Each kitty possesses its own digital genetic pattern, which in turn determines what type of offspring it will produce, in addition to its unique physical traits. This genome is stored in a smart contract, which is self-executing lines of code dependent on predetermined conditions.

Any two CryptoKitties can be bred together and produce offspring with their own distinctive cattributes. The immutable genotype stored in the smart contract likewise determines this new kitty’s phenotype. The GA mixes the code from both CryptoKitties to create new kittens, with the split between the parents varying every time they mate. This allows for unique kittens to be produced each time.

The game’s main premise is that players have to breed and sell their cats, which will allow them to earn ETH, especially for rarer cats. Generation and Cooldown are two crucial features of the game — both are necessary to understand which cats to purchase and breed during the selection process.

First, Generation determines how many generations a kitty is from its original parent. New Generation 0 kitties were released every 15 minutes during the first year of CryptoKitties. These kitties have no offspring yet, so if two Generation 0 kitties breed, they will produce Generation 1 offspring.

The Generation of each offspring is always one number higher than that of its parent from a higher generation. For instance, if a Generation 3 and a Generation 9 breed, their offspring will be Generation 10. This information can be found below each kitty’s photo, abbreviated as “Gen.”

Cooldown refers to a kitty’s breeding pace, such that a kitty with a lower cooldown will have a shorter breeding time. Kitties from higher generations will also have high cooldown rates. Both Generation and Cooldown affect the price of CryptoKitties, as these will determine how desirable they are on the market.

Can you play CryptoKitties on mobile?

Those looking to explore CryptoKitties gameplay on mobile can do so through an HTC mobile phone, which exclusively carries the United States mobile app of CryptoKitties.

Technically, however, players looking for information on how to play CryptoKitties on Android or iOS devices can simply access the mobile version of the website through a mobile browser. However, serious players looking for a dedicated app can currently only do so via an HTC phone.

How to get started with CryptoKitties

Here is a step-by-step guide on how to set up a CryptoKitties account to get started:

1. Create a MetaMask wallet

Players must first have an existing MetaMask wallet or create one. MetaMask will allow users to buy, sell and breed CryptoKitties. Once a wallet has been created, new users can proceed to the CyrptoKitties homepage, where they will be asked to link their MetaMask wallet upon clicking “Start” on the upper right-hand side of the screen.

2. Purchase Ether (ETH)

CryptoKitties can be purchased using Ether, which can, in turn, be bought from cryptocurrency exchanges, such as Binance and Coinbase. Ether can then be transferred to MetaMask to ensure that players have enough funds to purchase their CryptoKitties.

3. Create a CryptoKitties account

After connecting a user’s MetaMask wallet with CryptoKitties, they will be asked to provide their email address for important updates and key in a nickname they wish to use in-game. Players have the option to go through a basic “Kitten Class” tutorial where they will learn how to breed CryptoKitties.

How to play and earn in CryptoKitties

Once a player has successfully set up their CryptoKitties account, they can start playing the game. Below is a step-by-step guide on how to earn money playing CryptoKitties:

1. Buy CryptoKitties

Players can now view CryptoKitties for sale through the website or secondary NFT marketplaces like OpenSea. Offers can also be made to other players, allowing others to bid on cats even if they aren’t for sale. The owner can choose to decline or accept the offer. Each offer expires after three days.

New players have the option to purchase just one kitty to get started or buy a pair right away. If a player decides to purchase just one CryptoKitty, they can begin breeding it with a Sire from another player. If they purchase two CryptoKitties immediately, they can breed their cats for a much lower fee.

How much are CryptoKitties? Prices vary, but kitties may sell for as low as 0.001 ETH or as high as 600 ETH, maybe even more. Factors such as how rare a particular kitty is and how sought-after its cattributes are can affect the price it will fetch in the market.

2. Breed CryptoKitties

As mentioned, players can breed two of their own kitties together or breed them with a public Sire. It is best to breed kitties coming from the same generation to produce a kitty with a relatively low Generation as well.

To breed one’s own Kitties together, a player simply has to click on a kitty they want to assign as the “Sire” or the father. Then, click the “Breed” button and select “Sire with my Kitties.” Next, the “Dame” or mother cat can be selected to complete the breeding pair. To proceed, click “OK, give them some privacy” to allow the kitties to breed in peace.

To breed one’s Kitty with a public Sire, a player has to select a Sire from the marketplace and select the “Breed Now” option. They can then select a Dame from their own litter to form a breeding pair and then proceed with the option to give the Kitties privacy to breed. As previously mentioned, both options cost minimal fees in ETH, which goes to community-run bots and smart contracts.

3. Sell or Sire CryptoKitties

Once a player has produced new breeds of CryptoKitties, they can be put up for sale or Sired to the public. Each kitty in a litter will have “Sell” and “Breed” options, which will lead to auction pages.

Players can create a Siring auction by clicking “Breed,” which will put their Kitty up for Siring via the Siring market. “Sell” likewise creates an auction, setting the kitty up for sale on the marketplace. The player can select the starting price, ending price and auction duration.