In Helldivers, the players need to learn to coordinate their actions during chaotic combat, to complete objectives and to avoid friendly-fire casualties. The game is set in a procedurally generated universe where the community must fight three different enemy species to ensure the survival of Super Earth. Gameplay takes place on procedurally-generated missions where players must accomplish a series of objectives. Unlike many similar games where fighting certain enemies in a certain order is mandatory, the players make their own decisions about where to drop, whether to go on foot or in vehicles, in what order objectives should be completed and when to call down certain pieces of equipment, referred to as stratagems within the game. Before missions, the players select from a wide variety of weapons and equipment; some strategems drop a cargo pod containing heavy weapons or vehicles to be operated by players, while others consist of orbital strikes, airdropped minefields or other support firepower.
To win, players must fight or sneak through enemy-controlled territory, complete objectives, and call a dropship to extract them from the planet. Outside of certain trophies/achievements, there are no rewards granted for simply killing enemies, which are endless. It is possible to hold out indefinitely against waves of defenders, calling in more and more ammunition and defenses and racking up huge kill counts, without making the slightest progress toward winning the mission.