Killzone is a first-person action game set in the near future, during a period of planetary colonization. A savage conflict has broken out between the Earth-loyal forces of the ISA and a separatist, militaristic faction known as the Helghast. Following a devastating Helghast attack on an ISA colony, the player is thrust into the role of Jan Templar, a young ISA captain who must lead a ragtag group of soldiers on a suicidal mission behind enemy lines.