Dennman03

I always plan ahead. So we booked our upcoming Dec 2nd cruise 15 months ago. (1st cruise ever!)  Now I'm seeing all the cheap last minute deals, but I still feel better knowing we are all set, planned out, and paid for.  Plus I was able to get us an aft corner cabin on deck 10 aboard Liberty of the Seas, and I'm reading that is a really good thing!! 

You don't NEED passports but it's strongly encouraged that you do.  If you do not bring passports, then you do need to bring birth certificates.  
 
The reason why passports are better is because if you get stuck in another country, for whatever reason, you can easily fly home with passports.  It's a much bigger problem when you don't have them.