Horizon Zero Dawn is a 2017 action role-playing game developed by Guerrilla Games and published by Sony Interactive Entertainment. The first instalment in the Horizon video game series, it is set in a post-apocalyptic United States where large robotic machines dominate the Earth while humans live in primitive tribes with varying levels of technological development. The game follows Aloy, a young huntress who sets out to uncover her past. The player uses ranged weapons, a spear, and stealth to combat mechanical creatures and other enemy forces. A skill tree provides the player with new abilities and bonuses. The player can explore the open world to discover locations and take on side quests.