Castles Higher than level 10
From 11 onwards it's defense-nerd production-max nerds, rinse and repeat till level 20.
Forum Discussion
I just got my main castle to level 10. I know plan to get Lisa's castle to level 10, then Bart's after that. After I get all of them to level 10 I will start buying walls and towers to make them look good. After I buy a BUNCH of walls (I plan to buy extra in case I ever want to redecorate) then I will start upgrading my castles defense.
