User blog comment:Gourgeist/Attack on Titan Season 2/@comment-91.133.158.218-20140805113136/@comment-179280-20140805221932

Simple: If season 2 comes out in 2015, it will only be 12 episodes long. If it comes out in 2016, it will be 25 episodes long, and in either case, season 3 will be on 2018/19.