To gain access to Chao World you must first get the Chao Key. To get the Key you need to break open the Chao Crate in the action stage. In each stage there are 3 crates, the first contains the key, the second has 4 random animals from that stage, and in the final crate is a special animal (see the Animal page for details). When your in the Chao Lobby you can reach the 3 Chao Gardens. Time doesn't pass in a garden unless your in it. Chao Gardens appear in Sonic Advance 1 and 2, Sonic Adventure 1 and 2, Sonic Adventure 2 Battle, Sonic Pinball Party, and Sonic DX (Chao also appear in Sonic Advance 3 but it is not for raising them).

Each garden starts with a normal Chao egg. you can also buy eggs in the Black Market. You can hatch each egg 3 ways. First, you can shake it, this is the most common and is probably the best way. Second, you can throw it, this is the mean way to do it because the Chao will come out mad, though some people think it wont affect their attitude. And finally, waiting. This will take a little while. Some think if a Chao hatches normally, it will come out really happy, but this is not true. Chao's moods are random, accept for Chao obtained via breeding, those Chao usually get a mood from their parents (for More info go to the Moods page).

Giving your Chao lots of animals and Chaos Drives is good for making your Chao healthy. You can also give your Chao fruit from the Black Market. If you take your Chao to the Chao Doctor he will tell you what fruit your Chao likes (as well as many other things).Chao love to do activities like playing instruments and drawing, so you should take your Chao to the Chao Kindergarten. Buy seeds to grow trees and try to win all the Chao in the garden a watering can so they can water the tree to make it live longer. Beginners should go to "Extras" and then "Tutorials" and watch the Chao tutorial.

Chao from the Gamecube version have their personality altered more then Chao in the Dreamcast version. Basically this means that if you pet and hug your Chao a lot on the Gamecube version, it will become really happy and spoiled! But, if you do this on the Dreamcast it wont make much (if any) of a difference. Also, Chao on the Gamcube version seem to react different around each character, this means if you care for the Chao a lot with Shadow, it will like Shadow better thin other characters. This also means that if you abuse your Chao with Shadow, it will hate Shadow and it will start to change into a hero Chao. So basically Chao on the Gamecube are more life-like then Chao on the Dreamcast.