Developed and published by Sony Online Entertainment (which now encompasses Verant, creator of the genre-defining EverQuest), PlanetSide is designed to combine the best aspects of first-person shooter action and massively multiplayer persistent-world role-playing. Players enter a large and seamless virtual world of 13 separate continents, each up to 64 square kilometers in area. Instead of physical attributes or wealth, characters are defined by the certifications they choose. Different certifications allow the use of different types of weapons, vehicles, and gadgetry, most of which are easily available at any friendly supply base. Experience earns the chance to choose additional certifications.

Three opposing realms control this world. Choosing the realm with which to ally determines the player's place in the world, becoming like a home country in need of patriotic protection. Real-time battle rages day and night in PlanetSide, as the three factions fight for territory, power, and domination over all opposition.

The gameplay in PlanetSide is that of a next-generation first-person shooter. Players battle through 3D environments running on a new game engine developed specifically for this title. Unlike many contemporary online offerings, however, PlanetSide players do not enter discrete games for one-time deathmatch or capture the flag contests. Instead, battles take place as part of an ongoing campaign of warfare between the three opposing factions. The player's character can choose to join a registered outfit for regular missions of disciplined teamwork or join with a temporary outfit for one-time group missions. Even the player who decides to go it alone will perform solo missions that help to defend and strengthen his or her home empire. ~ T.J. Deci, All Game Guide