On our Alaskan Cruise they had Formal Night, Semi Formal Night, Freeze the Night Away (Frozen) and Pixar Night. For Semi Formal and Formal night most people made some effort. I was worried it would be all tuxedos and ball gowns(which we didn't pack) but most people were in dress pants and button down shirts or skirts or casual dresses. Frozen night I assume the little girls might have dressed up, but I rarely saw any kids during our entire cruise, so I couldn't really say and Pixar Day we had t-shirts to fit the theme, and I felt like we might have been the rare few. Not many people went all out for Pixar night like they do Pirates Night. We got the shirts just so we weren't the odd ones out, turns out not dressing up would have been the "norm" for that theme.