In Helldivers, the player needs to coordinate their actions during chaotic combat in order to complete objectives and to avoid friendly fire casualties. The game pits the player against three different enemy species and tasks them with ensuring the survival of Super Earth. Gameplay takes place on procedurally-generated missions where players must accomplish a series of objectives. At the start of each mission, the player can choose their loadouts and deployment positions, as well as using the game's unique stratagem mechanic to assist additional options to best suit the map or the player's preferred playstyle. For example, the player may choose stratagems that focus on providing additional firepower or mobility, or give themselves supportive abilities like calling in an airstrike on parts of the map. The game has a single difficulty option, though the player can then choose a hard or easy planet for their missions. This changed over the course of development. In each mission, the player must fight or sneak through enemy-controlled territory to complete the given objectives, then escape via a dropship. It is possible to fail some of the given objectives without immediately losing. It often benefits the player to avoid direct combat if possible, as the enemy has infinite reinforcements, and there are no in-game rewards for simply killing enemies. The game keeps many of the mechanics common to the genre, like Fog of War and a map that shows any enemies the player(s) can currently see. The enemy will patrol their territory, impeding the player's attempt to complete the given objectives. Enemy units that come in contact with the player(s) will try to raise an alarm, which will result in continuous waves of enemy reinforcements for as long as the alarm remains active. The player can prevent an alarm by avoiding enemy patrols if possible, and can cancel one by defeating all units currently aware of the player or by fleeing the area. Once all mission objectives are successfully completed or failed, the player is then required to call in a dropship and escape with all their remaining units. This takes 90 seconds and draws enemy attention to the landing zone, resulting in heavy fighting. Entering the dropship completes the mission.