Look around on the marketplace to find yourself some Kitties. If you’ve found a Kitty you’d like to buy, click on the cat and hit the “Buy now” button. A new page will open so you can double-check the Kitty you’re about to purchase. If everything seems in order, click on “OK, buy this Kitty”. You’ll be prompted with a MetaMask transaction window. Click submit to purchase the Kitty. It may take a couple minutes to show up on your profile. This all depends on the Ethereum network.
Offers are another way to buy cats. Using the game's Offers system, players can make a bid in ETH for any Kitty in the game, even if they're not currently up for sale. Once an offer is made, the owner can choose to accept or decline it. Offers expire after three days.
There are two ways to breed a new Kitty: breed two of your own Kitties together, or breed with a public sire. Best practice is to breed two Kitties of the same generation, since the offspring’s generation (gen) will be the highest generation of both parents plus one. If you breed a Gen 3 and a Gen 4 Kitty together, you get a Gen 5 Kitty. If you breed two Gen 3s, on the other hand, you get a Gen 4.
If you want to breed two of your own Kitties together, go to your litter and click on a Kitty you want to make the father (the Sire) in your breeding. This cat will show a “Breed” button. Click on that, then click on “Sire with my Kitties”. After that, you get to choose the Dame (or, the mother) for your breeding. Once you’ve selected a breeding pair, hit “OK, give them some privacy” to open a transaction window and let those Kitties make some magic.
Once you’ve got your paws on some CryptoKitties, you can put them up for sale or Sire them to the public. If you go to your litter and click on one of your Kitties, you’ll see the buttons “Sell” and “Breed”. Both of these buttons lead you to a page where you can create an auction. “Breed” lets you create a Siring auction, which means other players can breed with your Kitty through the Siring market. “Sell” creates a sale auction. Other players can find your sale auction on the marketplace. You get to pick the starting price, the ending price, and the duration of the auction.