In NiGHTS into Dreams, Elliot Edwards and Claris Sinclair are the two teenagers who explore Nightopia through their Dreams with NiGHTS. There are seven dreams in total; Spring Valley, Splash Garden, Mystic Forest, Frozen Bell, Soft Museum, Stick Canyon, and a shared dream of Twin Seeds City.
In NiGHTS: Journey of Dreams, William Taylor and Helen Cartwright can access three separate worlds; or Dreams, each created by their Ideyas including one shared dream. Much like NiGHTS into Dreams; there are seven dreams in total: Aqua Garden, Pure Valley, Crystal Castle, Lost Park, Memory Forest, Delight City, and the shared dream of the city Bellbridge.
- The word "nightopia" derives from both "night" and "utopia".