In 7 Days to Die, the player spawns into a randomly-generated world or the preset world of Navezgane, Arizona, with the objective of surviving for as long as possible against the elements and the zombie hordes. As a survival game, the player character is in constant need of water and food for sustenance, as well as being vulnerable to injury and illness. The game is voxel-based (similar in some aspects to Minecraft, but with smooth terrain), allowing for simple building and destruction of objects in a physics-simulated environment (for example, building a structure with no support such as pillars and walls can lead to its collapse).[6][7] Objects in the world degrade through use, so the player has to search for or make new tools as the game progresses. The player can also gather and create materials—from nature and the remnants of human civilization—to construct these necessary items.[8][9]
While the game includes wildlife that can be hunted for food or will hunt the player, the main hazard is zombies, which are affected by the game's day/night cycle—during the day they are relatively slow-moving and easy targets that can only detect the player at relatively close ranges, but at night they become feral, which makes them move much faster and thus greatly increases their threat. As the in-game days progress, tougher and more aggressive variants begin to appear.[10] Stealth and distraction can be used to avoid unnecessary conflict. They are also drawn to areas of human (i.e. player) activity, and will relentlessly attack anything that impedes their movement until they are killed or the obstacle is destroyed, including player-built fortifications. Should they detect the player, zombies will apply the same single-minded pursuit until the player is either dead, or leaves the immediate area.
The game's title is a reference to an important Blood Moon event that occurs every seventh day of in-game time, whereby hordes of zombies and wild infected animals attack the player's current location en masse. Unless sufficient preparation has been made and defenses constructed, the player will quickly be overwhelmed.
The world of Navezgane is composed of multiple biomes, or geographic areas. These include dry deserts, temperate forests, snowy fields, as well as a scorched wasteland. Each biome has unique resources that can be obtained, thus encouraging exploration across the map by players.
