Getting an invitation to a wedding labeled "black tie optional" can leave you searching through your closet for something that fits the bill. It's one of the more ambiguous dress codes, but you should still strive to meet expectations, particularly so you don't end up over- or under-dressed for the event. By understanding the etiquette for a black tie optional event, you'll know exactly what to wear anytime those words show up on an invite.
Black tie optional means just what it says: black tie is optional for this event. It means that the event will be formal enough that some guests can choose to wear full black tie -- meaning a tuxedo -- but that it's an optional suggestion. If not completely formal wear, the dress code is still very formal and a step ahead of semi-formal and cocktail dress codes. In short, expect to dress up, even if you're not planning on dressing like you're attending the Oscars.
At a black tie optional wedding, men are expected to wear one of two options. The first, of course, is a classic black tie tux. However, since it's optional, a dark suit worn with a conservative tie would be just as acceptable. Shoes should be formal and well-polished, remembering that it's meant as a formal affair. Leave the sneakers at home.
Women have a little more wiggle room when it comes to interpreting black tie optional wear for a wedding or other formal event. Floor-length gowns are always permissible and the most formal outfit. If you lack a full-length gown, a special-occasion cocktail dress -- one adorned with sequins and worn with formal shoes, for instance -- would work as well. In some cases, even separates can work for black tie option, as long as the fabrics are formal, like chiffon and silk. Absolutely no khaki or denim.
If your closet isn't full of floor-length, Oscar-worthy gowns or tuxedos, never fear. The accessories are where you can make even a simple getup more luxe for a black tie optional affair. Men can add flashy cufflinks to an otherwise basic suit and women can use statement jewelry -- think jeweled necklaces, drop earrings or cocktail rings -- to turn a basic black cocktail dress into black tie optional-appropriate outfits. Grab luxe heels and a beaded clutch to finish out a glam look that matches up with the event's dress code.
Remember, while it might not be your favorite style, it's important to pay attention to the dress code, especially if the affair is more formal. It's one night and who knows, you might actually like playing dress-up every once in a while.