1. The document discusses the concept of "dress-up play", which is a significant pattern of play for both children and adults, especially females, that involves roleplaying and assuming different identities through costumes. 2. Dress-up play has been largely ignored in traditional game studies but can involve both structured and unstructured forms of play. It is becoming more prominent in digital games through features like avatar customization. 3. Dress-up play serves important social and self-expressive functions for both children and adults, allowing people to explore different aspects of their identity and personality through performance and imagination.