The planet Na Pali is home to the technologically primitive and pacifistic Nali who, during the events of Unreal, have been subjugated by the alien Skaarj. Na Pali is rich in the mineral Tarydium, which is used as a power source in the starships of the Skaarj and other spacefaring races. The abundance of Tarydium also gives Na Pali a powerful gravitational field, which often pulls meteors and even whole starships to the planet's surface. This gravitational field is the reason the prison ship Vortex Rikers crash landed on the planet, bringing Prisoner 849 (the player character) with it.
Na Pali has a wide range of environments, though much of the surface is made up of lush rainforests, vast gorges and caves filled with Tarydium. The Nali live in small villages made up of huts and medieval-style architecture, with cathedrals and castles in its most highly-populated centers. After the Skaarj invasion the savage aliens established their own bases on the surface, their high-tech installations providing a stark contrast to the simple buildings of Na Pali's natives.
The Nali also live in an off-world settlement called Na Pali Haven. This massive city, built on floating platforms in the sky which are held aloft by rich Tarydium reserves, was considered the last free haven of the Nali until the Skaarj overran it too and established a garrison to keep the population in line.
It is unclear what becomes of Na Pali and its inhabitants after the end of Unreal and its expansion, though in the novelization of the games it is said that Na Pali is freed from the grip of the Skaarj through the combined efforts of the surviving human prisoners and the Nali resistance.