Nicole Lazzaro's 4 Keys 2 Fun theory offers a framework for understanding what makes activities enjoyable, breaking down fun into 4 categories:

• Easy fun (novelty): Comes from exploration, creativity, and playful interaction. It involves lighthearted activities that spark curiosity and joy.
• Hard fun (challenge): Arises from overcoming difficult tasks and achieving challenging goals.
• People fun (friendship): Revolves around social interactions, competition, and cooperation.
• Serious fun (meaning): Engages users in meaningful activities that have a positive impact on themselves and the world. This includes giving to others, collecting items, and unlocking achievements that carry personal significance.^[1]