If you’re 14 or older, the clock has struck twelve on your ability to dress up as your favorite character at a Disney theme park.
The success of Disney theme parks is in large part due to their strict rules and regulations, among which are rules for what guests may or may not wear. According to the Disney resorts dress code, costumes or masks may not be worn by guests who are 14 years of age or older (though exceptions are made for the latter in case of medical need). Refusal to comply with this dress code can result in a guest being refused admittance to the park or even getting kicked out.
The rule seems to be, in part, due to the reasoning that the only adults in costume at the parks should be the Disney Cast Members dressed as human characters for meet and greets.
This doesn’t mean you have to dress entirely plain, however. Hats, wigs, and other headgear are totally fine as long as they don’t cover your face, and accessories such as toy swords (that don’t look real), lightsabers (made of plastic or even churros), transparent wings, and tutus are allowed as well. You’re also more than welcome to wear a cape, as long as it doesn’t fall to below your waist!
Taking a trip in October, however, could be your chance to dress up, as this dress code is relaxed for events like Mickey’s Halloween Party. However, dressed up guests may not pose for photos with other guests nor can they sign autographs as their characters. For those who can’t make it out to a Disney park for Halloween, however, there are adult Disney-themed events such as bar crawls where dressing up is strongly encouraged.
Protecting the Disney brand doesn’t seem to be the only reason for this rule. Safety is also a concern. Even at special events where they’re allowed, costumes cannot contain anything offensive or violent, nor can they have anything sharp or resembling a weapon. Costumes that are layered or have props surrounding you can be subject to more screening and, as a result, are discouraged. Long costumes that reach the ground or can drag are also not allowed. While children ages 13 and under are allowed to wear costumes and masks, the masks must not cover their whole face and their eyes must be visible.