If you purchased a key from a retailer (like CDKeys or Green Man Gaming), you will receive a 16 or 19-digit alphanumeric code via email.
Serial numbers for these games are "one-time use." If a key is posted publicly on a forum, it has already been used and blocked. avatar pc game serial number
This was originally found on the back of the manual. It usually follows a format like: AVA-XXXX-XXXX-XXXX-XXXX . If you purchased a key from a retailer