No, forced dressing up rarely works well. You immediately create a group that opts out because they feel uncomfortable or didn't have time for a costume.
Make it accessible: give a clear dress-code suggestion. Make sure someone in a smart suit or dress also fits in. Let the setting, the music and the entertainment carry the theme. Whoever does show up in costume, reward with a subtle compliment at the door.
Want to know more about organising a themed party? Read our article →