The player can interact with survivors outside of their group: trading with them, helping them or recruiting them. The game features two relationship meters, the first determines if a survivor can be recruited, and the second dictates if they can be controlled. Only one survivor can be controlled at a time, though the player can ask an AI-controlled survivor to accompany them, and in certain missions, one or more AI-controlled survivors will accompany the player.
The Storyline mode features around 150 characters, with varying facial features and clothing. Each character has a fixed set of “traits” which give them advantages or flaws (such as tire out more easily, or can improve a certain skill faster). Except for the story-related characters, most characters can be assigned to survivor groups and be recruited. Each character also have an “attitude” parameter, affected by game events (a near death experience, death of another character, or having accomplished a difficult task). These attitudes can affect their behaviors, sometimes requiring player intervention.
Zombies are the main threat in State of Decay. They respawn infinitely, are attracted to noise, and are capable of sprinting nearly as fast as the characters. Player can choose to confront them directly, use stealth to sneak past them, or divert them using items like firecrackers. In addition, there are special types of zombies, such as the animal-like “Ferals” or the tank-like “Juggernauts” that are quite dangerous in one-on-one confrontations. The game doesn’t have human enemies, only zombies.
The game features over 100 different weapons, including around 30 melee weapons that can be found while scavenging (they cannot be crafted). Melee weapon and firearms are further divided into sub-categories, which have different attack animations and effects. All weapons have a durability rating, and will break when used excessively without repairs. Besides weapons, the player can find or create various consumables to improve their chances of survival, such as painkillers and pipe bombs.
Besides walking, the player have access to several types of car, each with its own parameters like maneuverability and speed. All vehicles can be damaged and destroyed when running over zombies or hitting obstacles, although they can be repaired at home base.