CryptoKitties

A computer running Chrome or Firefox

Can I play on a mobile device?

You sure can! Mobile wallets like Coinbase Wallet and Trust support CryptoKitties. Plus, we’re building a mobile app for CryptoKitties, so you’ll soon be able to play everywhere!

Can I log in from multiple computers?

You can use CryptoKitties from multiple computers as long as you have your digital wallet installed on both.

Can I use a different browser?

We recommend sticking with Chrome or Firefox. It may be technically possible to use another browser, but we can’t guarantee optimal performance, so you may want to steer clear.

A digital wallet

Installing your digital wallet

• To use CryptoKitties, you need a digital wallet. We support all digital wallets, but recommend Metamask for the best CryptoKitties experience.
• You’ll need to put money in your wallet to make your first purchase. We can show you how to do that, too.
• Note: A digital wallet acts like a bank account — treat it with respect and make sure you don’t forget your password or lose your recovery kit.

What is a “wallet address”?

Your public wallet address (e.g. 0xaba935f589805095a892ecefdb6eb83eff45d67) is a unique identifier for your wallet. It’s like a name. You can share it freely with others, and it’s used to direct assets to your wallet.

Ethereum, a digital currency

What’s ether (ETH)? Why do I need it?

• Ether is a digital currency that powers the Ethereum network, which is what CryptoKitties is built on. Ether acts like any other currency — its value fluctuates with the market.
• You need to convert your currency (e.g. USD, CAD, GBP) into ether to pay for things — such as CryptoKitties — on the Ethereum network.

How do I get a CryptoKitty?

You can get a CryptoKitty in one of three ways:

• 1. Buy one from the Marketplace, which you can look through using the “Search” tab.
• 2. Breed two CryptoKitties together.
• 3. Receive one as a gift from another player (you still need a wallet to receive the Kitty).

How much does it cost to play CryptoKitties?

• It costs money to buy a Kitty or breed Kitties. There’s also a small ‘gas’ fee paid to conduct transactions on the blockchain.
• Buying: When you buy a Kitty, there’s no standard price. Users choose their own starting and ending price when they create an auction for their Kitty, and the price goes down until the Kitty is bought or the auction ends. Once an auction ends, the Kitty stays for sale at the final low auction price until its bought or the owner cancels the auction.
• The CryptoKitties team releases a new “Gen 0” CryptoKitty every fifteen minutes. These Generation 0 Kitties started it all! They are born from the “Kitty Clock” and they have no parents. Only 50,000 will ever be created — collect them before they’re gone! The starting auction price of Gen 0 Kitties is determined by the average price of the last five CryptoKitties sold from the Kitty Clock, plus 50%.
• Breeding: Every time you breed your Kitties, there’s a birthing fee. The birthing fee is collected by CryptoKitties, but it doesn’t go directly to us. It covers the cost of writing your new CryptoKitty onto the blockchain. From time to time we adjust the birthing fee to match current conditions in the Ethereum network.
• If you choose to Sire a Kitty from the Marketplace instead of breeding two of your own Kitties, you also need to pay a Siring fee, which is set by the owner of the Kitty you choose to Sire with.
• Gas: Transactions are secured on the Ethereum blockchain, and it costs a small fee for its miners to process the transaction. This ‘gas’ fee applies to every transaction in CryptoKitties.

How many CryptoKitties do I need to get started?

• Just one! However, we recommend starting with two so that you can breed them together.

Where’s my Kitty? I just bought one but it’s not showing up in my account!

• Transactions on the blockchain can take a few minutes to process, and then it can take a few more minutes for our website to sync with the blockchain. In other words, Kitties are typical cats — they do things on their own schedule.
• Don’t worry, though. If the transaction was successful your Kitty belongs to you, and it will show up. The blockchain doesn’t lie.

How do I sell or Sire out a CryptoKitty? How do the auctions work?

• After clicking on your Kitty, you will see buttons near its name for selling and Siring.
• Kitty auctions can go up or down in price, and when the time expires, the price stops moving. The Kitty is only returned to you if you cancel the sale or Siring, or if your cat is Sired with. Putting a Kitty up for sale or siring is a transaction on the blockchain, so you have to pay a gas fee.

I sold a cat. Where’s my ETH?

• If you successfully Sired or sold a cat through our marketplace, the other user definitely sent ether. Since the user paid for the Siring or sale through our smart contract, the payment isn’t reflected as a typical IN/OUT transaction in Etherscan. (Etherscan is a read-only interface for the Ethereum network that shows all events on the blockchain.)
• To see the ether generated from CryptoKitty auctions, check the Internal Transactions tab for your address in Etherscan.

When I tried to buy a Kitty, it said, “Looks like you can’t buy this Kitty right now.” What gives?

• This message is triggered when someone else buys the Kitty before your transaction goes through, or because the Kitty’s owner canceled the sale auction.
• The Marketplace stops you from submitting transactions that will likely fail (to save you gas fees).

I can’t access my wallet. Can you recover my Kitties?

• Unfortunately, no.
• If you lose access to your wallet, we can’t recover your cats. It’s not an issue of it being against our policy or being too difficult; it’s literally impossible.
• Our smart contracts secure each CryptoKitty so that the developers can’t edit, access, or reassign them. This protects your Kitties from hackers and anyone else who would steal them. Unfortunately, it also means we can’t simply ‘recover’ a CryptoKitty.

How much does it cost to make an offer on a cat?

Every offer includes a fee of 3.75% of the total offer value. The entire sum of both offer and fee is collected up front, but how much the bidder actually gets charged at the end of the offer depends on what happens:

• If the owner accepts the offer, you pay both the offer amount and the 3.75% fee. If you cancel your offer early, you fully recoup your offered amount but still pay the 3.75% fee.
• If your offer is outbid or if it expires, your ether is automatically returned, but instead of the 3.75% fee you’re charged a flat rate of 0.001 ETH.
• If an owner declines your offer, you aren’t immediately refunded. You can choose either to cancel early and pay the 3.75% fee, or wait for the offer to expire after one day and only pay the 0.001 ETH flat rate.

Where does my ether go when I place an offer?

When you make an offer your ether is held in escrow by the offers smart contract. While in escrow it’s untouchable unless your offer is accepted by the owner or canceled by you. You can cancel your offer any time to retrieve your ether, but you will be charged the 3.75% fee. Alternatively, you can wait until your offer reaches its one-day expiry and pay only the 0.001 ETH flat rate.

What happens when an offer is made?

We notify the owner of the Kitty via email.

What happens when an offer is declined?

We notify the bidder that their offer has been declined by the seller and that they must wait until their offer expires or cancel the offer to get their refund.

Is my CryptoKitty a Dame or a Sire? A boy or a girl? A dad or a mom?

• It’s the 21st century; let’s ease up on the labels.
• Every CryptoKitty can play the role of Dame (i.e. mother) or Sire (i.e. father). However, a CryptoKitty can only be one at a time. For example, your Dame can’t Sire while they’re preggers — and vice versa.

How do I breed my Kitties together?

• There is a button near your Kitty’s name for breeding. It walks you through the process.
• There is a breeding fee, paid each time a pair of Kitties are bred.

Where’s my kitten? I bred two cats but the kitten isn’t showing up!

• After the “Preggers” timer is up, you should receive your new Kitten pretty quickly. Sometimes, though it can take a bit of time for the blockchain to process the new birth and for the kitten to appear on the website.

Why does it cost ETH to breed a CryptoKitty?

• There are two parts to the cost of breeding new Kitties: a transaction fee and a birthing fee. Every transaction sent to the Ethereum network requires ‘gas’; the gas fee is given to Ethereum miners. The birthing fee is necessary to create the new Kitties on the blockchain at the proper times.
• The breeding fee is set based on current conditions in the Ethereum network.

How do I breed with other users’ Kitties?

• You can breed with a Sire from the Marketplace by paying the listed Siring fee (along with the birthing fee). The search bar will help you filter the Kitties that are available for Siring.

How often can I breed my Kitties?

• A CryptoKitty can’t breed while it’s expecting offspring or recovering from Siring. This is called its “cooldown”. Every time a CryptoKitty breeds, its cooldown period increases.
• High generation Kitties are born with longer cooldown periods than low generation Kitties.
• Learn more about cooldown here.

How do a CryptoKitty’s ‘genes’ work?

• Each CryptoKitty has probabilistically unique ‘DNA’ that affects not only what it looks like, but what its offspring will look like.
• Basically, each CryptoKitty is composed of visible Cattributes, but also a variety of traits that can only be found through breeding. Certain genetic combinations can unlock a mutation — a whole new characteristic! For example, a green-eyed cat and a blue-eyed cat might unlock a purple-eyed cat (NOTE: This example isn’t true, but the concept is).
• Want to learn more about CryptoKitties genetics? Check out our guide.

Will my Kitty ever become sterile (unable to breed)?

• Nope!

Can my Kitty breed with its siblings or parents?

• Uhhh… no. But it can breed with its aunts, uncles, cousins, grandparents, and its weird neighbour from down the street. We don’t judge.

Does it matter which cat I use as the Sire and which cat I use as the Dame?

• Genetically, no. The odds of inheriting traits from the Sire are the same as they are from the Dame.
• If you want your kitten quickly, however, pick the Kitty with the fastest cooldown speed as the Dame.

Animations are slowing down my breeding speed. Is there a way to turn them off?

• Go to your profile, click on the “settings” button below your name and check the “Auto-hatch all my Kitty eggs” preference.

What are Fancy Cats, Exclusive Cats, and Special Edition Cats?

• Fancy Cats Fancy Cats are CryptoKitties with custom art. Fancy Cats are generated when users create a cat with the right combination of traits. That special recipe of Cattributes is what turns a Kitty into a Fancy Cat! Every kind of Fancy Cat has a limit (of either time or number) of how many of its kind may be bred. After that limit is reached, no more Fancies of that type can ever be created.
• Exclusive Cats also have special artwork, but they can’t be bred using a recipe like Fancies. Instead, we drop them into the game on very special occasions. They can’t be replicated, making them extremely rare.
• Special Edition Cats have special artwork, like Exclusive Cats, but they’re made in much bigger numbers. They’re still limited, like Fancy Cats, but they can’t be bred.

What determines the generation of a cat?

• Every CryptoKitty is born with a generation one higher than its highest-generation parent. For example, a Gen 3 cat and a Gen 15 cat will produce Gen 16 offspring.
• We release a “Gen 0” Kitty every 15 minutes. There will be 50,000 total; after that, they’re gone! All the other generations are created through breeding.
• Generations affect a Kitty’s natural-born cooldown speed. The higher the generation, the slower the cooldown.

What is “cooldown”?

• Making babies is hard work. Every Kitty knows that. So whenever your Kitty breeds, it needs time to rest before it can breed again. This is called the Kitty’s “cooldown”. The more a Kitty breeds, the more time it spends cooling down.
• A Kitty’s cooldown at birth is determined by its generation (not genetics). The higher the generation, the slower the cooldown. Learn details about cooldown here.

Help! My Kitty has been stuck in cooldown longer than it should have!

• Our website usually experiences some site lag as it syncs with the blockchain. Waiting patiently is usually the best solution (though we recognize it’s not the most desired one), as these problems generally resolve themselves with a bit of time.
• If your Kitty is stuck for over 30 minutes, we can reset your cat manually — please reach out to meow@cryptokitties.co with “stuck in cooldown” as the subject line. Make sure to include the Kitty’s ID number in the email body so that we can solve your issue as soon as possible.

Can I send a Kitty to my mom?

• Yes! You can send a Kitty to anyone who has a digital wallet. Use the ‘Gift’ button in your Kitty’s profile, and input the recipient’s public address (e.g. 0xaba935f589805095a892ecefdb6eb83eff45d679).
• Gifting a Kitty only costs a small transaction fee.

What are Mewtation Gems and Family Jewels?

• The first Kitties that introduce a new Cattribute to their family tree are rewarded with a Mewtation Gem. The type of Gem (diamond, gilded, amethyst, or lapis) depends on how early on the Kitty discovered the Mewtation.
• After a Mewtation Gem is awarded to a Kitty, all of its descendants have the opportunity to claim it as a Family Jewel (shown next to the Cattribute) if they also share that trait. Even if it disappears for several generations, the jewel is reclaimed by any descendant who inherits or discovers the same Cattribute as its jeweled ancestor.
• Learn more about Family Jewels here.

What are Purrstige traits?

• Purrstige traits are special traits available for a limited time.
• Purrstige traits require a specific recipe which always includes one of the highest three tiers of Purrstige genes. If you’d like to learn more about trait tiers, check out our guide here.
• Want to know more about Purrstige? Keep an eye on Twitter, where we release information on how to gain first access to these special traits.

What are the Cat Codex and Special Cat Codex?

• The Cat Codex, which appears under the ‘Your Kitties’ tab on the website, is a list of Cattributes. It shows you which traits your cats currently have, and which ones you’re missing. The Special Cat Codex tracks the Fancy and Exclusive Cats that you collect. You can complete your Codex by buying and breeding cats with traits that are new to your collection, but remember, new Cattributes are continuously being discovered, so keeping up is part of fun!

How many possible CryptoKitties are there?

• There are literally billions of possible genetic combinations.

How many CryptoKitties exist in total?

• There will never be more than 50,000 Gen 0 Kitties, but there is no limit to the number of other Kitties that can be bred.

How is the CryptoKitties team making money from CryptoKitties?

• When you buy a Gen 0 cat — these cats are released every 15 minutes — we get that income. Otherwise, we earn 3.75% of each transaction on our marketplace.
• Note that we made the marketplace to make our game as easy as possible to use. It’s possible to do whatever you want with your cats outside of our marketplace without paying us a cent.

What’s Etherscan?

• Etherscan is a read-only interface for the Ethereum network. It tells you everything that’s happened on the blockchain. It helps you verify that transactions were successful, and tracks other helpful details about transactions and addresses.

Why did my transaction fail?

• If your transaction failed, it was probably because someone else bought the Kitty right before you did. Other possible reasons a transaction might fail: manually setting the gas limit too low, or bidding on an ascending auction that increases the price of the Kitty before your bid goes through.

My transaction failed but it still charged me gas.

• Gas is paid whenever a request is processed on the blockchain. Even if a transaction fails, it still takes computing power to determine whether or not the transaction can succeed. The Ethereum network charges gas for the operations executed up until the transaction fails. These transaction fees are not paid to the CryptoKitties team, but to the Ethereum network and miners.

My transaction timed out.

• When a transaction “times out,” it doesn’t mean the transaction has failed, only that the Ethereum network is very busy. As a result, CryptoKitties won’t update until the transaction is finalized in the network.
• This can occur because of high gas prices or a spike in network congestion.

Tell me more about ‘gas’.

• ‘Gas’ is a shorthand used to describe the cost of powering a transaction or contract in Ethereum, which is the blockchain network that CryptoKitties is built on.
• Because blockchain is decentralized, every transaction is distributed through multiple computers, not a central server. This ensures each token — in this case, each CryptoKitty — is secure and one-of-a-kind. It also takes a lot of computational power, which is covered by the cost of gas.
• ‘Gas’ is composed of two parts: Gas Price and Gas Limit. Gas Price is what you offer to pay the miners (in a tiny measurement of ether called “gwei”) for each operation to execute the smart contract. Gas Limit is how many operations you let them to do before they run out of gas and drop the transaction.
• 1 gwei = 1/1,000,000,000th of an ether.
• You can get more information here and here.

I didn’t receive ether for a sale or Siring.

• If you successfully sired or sold a cat through our marketplace, the other user definitely sent ether. Since the user paid for the siring or sale through our smart contract, the payment is not reflected as a typical IN/OUT transaction in Etherscan. To see the ether generated from CryptoKitty auctions, check the Internal Transactions tab in Etherscan.

Are CryptoKitties like Bitcoin?

• CryptoKitties are NOT a cryptocurrency. They’re a cryptocollectible. The real-world analogy for a cryptocurrency is dollars or pounds; a cryptocollectible’s real world analogy is closer to assets like baseball cards or fine art.
• As dictated by the smart contract, any CryptoKitty you own belongs to you. Like any product or property you can own, the market price is determined by supply and demand.

Help! My problem wasn’t addressed here. How do I contact the CryptoKitties team?

• You can contact us at meow@cryptokitties.co. Please include any relevant Kitty IDs, links, or transaction hashes so we can support you as quickly as possible.
• You can also check our Discord community channel. Your fellow players are often just as helpful as we are, and usually much quicker at addressing your concerns.

What is Discord?

• Our Discord group is the official gathering place for our community. Players come to learn about the game, chat about their strategies, and participate in community events. Join us!

Where do I find out about game updates?

• We discuss all the happenings on our official blog, including peeks into our Kitty-making and leaks about our game-making. You can access our blog anytime from the link at the top of the site.
• You can also sign up for our weekly newsletter if you take your news with a healthy serving of cat puns.

Do you ever drop hints for Fancy Cat recipes? Is there any way to get Kitty swag?

• Oh yes, definitely. The source of secret perks are our social channels: Twitch, Twitter, YouTube, Facebook, and Reddit. Follow us there for access to hints, contests, and giveaways.

What else can I do with my Kitties?

• The great thing about the blockchain is that anyone can build games and features for CryptoKitties, with or without our involvement. We call this expansive world the “KittyVerse”, and we’re working on a landing page to bring you all our favourite experiences. For now, here are a few fun things that community members have built:
• kittyhelper.com, power search tool for CryptoKitties
• Kitty.Family, see your kitty’s family tree and genes
• KittyNews, latest news, sales information and floors
• CKBox, a free Chrome extension that helps you find out useful information about CryptoKitties
• Heaven.cat, helper & gene search tools for breeders
• WrappedKitties, ERC20 token backed 1 to 1 for CryptoKitties
• KotoBaza, Russian language blog with lots of useful information about CryptoKitties
• CatatonicClub, automated breeding tool

How do I contact the CryptoKitties team?

• You can contact us at meow@cryptokitties.co. Please include any relevant Kitty IDs, links, or transaction hashes so we can support you as quickly as possible.