In Killzone Shadow Fall for PS4; Users are encouraged to create their own custom map presets, which then can be shared with others or promoted by the community. Abilities and weapons are unlocked from the start. The class system has been simplified to just three: Assault, Scout and Support. The player unlocks skill enhancements based on completing challenges unique to his class. Alongside competitive multiplayer, a 4-player online co-operative mode was introduced with the Intercept expansion pack. Following the Petrusite detonation that rendered the planet Helghan uninhabitable in Killzone 3, the ISA grants refuge to the Helghast survivors on the planet Vekta, allowing them to colonize half the planet, with that half of the planet dubbed New Helghan.
A massive security fortification called The Wall is constructed to separate the two civilizations from each other, due to the resentment they bear over the previous war. Both the Vektans and Helghast routinely perform covert operations against each other in the hope of finishing the war each claims the other started. The majority of the game takes place in Vekta City, home to the Vektan Security Agency headquarters, as well as a prison in New Helghan, and Helghan, the original home to the Helghast, now dead and shattered due to the Petrusite detonation. Following the Petrusite detonation that rendered the planet Helghan uninhabitable in Killzone 3, the ISA grants refuge to the Helghast survivors on the planet Vekta.
The game begins in the year 2370, several years after the construction of 'The Wall', during the forced relocation of Vektans out of New Helghan. Michael Kellan and his 5 year old son, Lucas, attempt to sneak through New Helghan to The Wall. Along the way, they meet Sinclair, a Shadow Marshall, who aids them in making it through to safety. Just as the group makes it to The Wall, Helghast forces spot them and kill Michael. After Sinclair dispatches the remaining forces, he promises Lucas that he will look after him. A brief cutscene plays, showing Lucas rising through the ranks of the Shadow Marshal Academy, eventually becoming a full-fledged Shadow Marshal and working under Sinclair's command.