"Animal Jam" headquarters releases codes on the game's blog, "The Daily Explorer," at DailyExplorer.AnimalJam.com, as of 2015. Headquarters also occasionally sends codes out to users via Jam-A-Grams and puts them in National Geographic Kids Magazine.
Rewards vary depending on the code, but common rewards are a set amount of gems or a special item. Most codes have expiration dates.
To redeem a code, the player visits the AnimalJam.com homepage and enters his user name and password. He checks the I Have A Code To Enter box, and enters the code. He clicks Play, and the game automatically applies the reward to his account. Another option is the Redeem page on AnimalJam.com.