Board Thread:Questions and Answers/@comment-97.64.173.28-20150526154919/@comment-24659969-20150527025708

There are two kinds of serial code in BC.

The first one is referral / friend code which separated into two codes, one for Moneko and the other for Bean cat. When you input the code you got from someone, it can give you 10000 exp, while the referrer will get bonus according to how many people used his code with the top prize is unlocking the said cat unit (10 refferal for moneko and 3 for bean cat).

In theory, one account is limited to inputting one code for each moneko and bean serial code. But people can simply delete their app and starts over or using backups to point before code inputing to be able input certain codes multiple times.

The second one is real-life code, these codes are obtained thru BC merchandise or stuffs like that. For example in BCKR, if you input the product code for the BC plushie you bought from on-web store into the game, you will receive a special code which can be used to unlock certain cats.