I think the black and white night is a great opportunity for those who wish to dress up, to do so, and it's usually the night for getting those pretty pictures taken! The theme nights are just for fun -- feel free to dress for them -- feel free not to. The ship is always rocking with a party, and it's fun to be there having fun, laughing, dancing, drinking, making friends, whether you are dressed in theme night attire or not. Personally, we have only dressed for 3 theme nights; 1 Halloween (although we were sadly outdone by the super Halloweener's LOL), 1 formal night (which really wasn't that formal, but formal for us) and 1 white night. It didn't keep us from the party not dressing up though, that's for sure. It's a fun option, like I said, so do it, or don't. FEEL FREE