The Long Dark is set in an open world environment and played from a first-person perspective. The game takes place in the frigid Canadian wilderness where the player assumes the role of a crash-landed pilot struggling to survive after a geomagnetic storm. The environment is divided up into a number of regions: "Mystery Lake", "Coastal Highway", "Pleasant Valley", "Forlorn Muskeg", "Desolation Point", "Timberwolf Mountain", "Mountain Town", "Broken Railroad", "Hushed River Valley", "Bleak Inlet", "Ash Canyon", and “Blackrock Mountain”, some of which are interconnected. The gameplay is stated by the developers to be a "survival simulation that accounts for body temperature, caloric intake, hunger/thirst, fatigue, wind-chill, wildlife, and a host of other environmental factors." There are three game modes available to the player, "Story mode", "Survival mode", and "Challenge mode".
The game's map is divided up into a number of regions: Mystery Lake, Coastal Highway, Pleasant Valley, Forlorn Muskeg, Desolation Point, Timberwolf Mountain, Mountain Town, Broken Railroad, Hushed River Valley, Bleak Inlet, Ash Canyon, and Blackrock Mountain. Some areas are interconnected.
Survival mode :
Survival mode is set in an open world environment where the player can choose the region they wish to spawn in, and may access any region in the game. The objective is for the player to survive as long as possible by scavenging and utilizing whatever resources they may find within the world. This includes commodities such as food, water, firewood, medicine, and tools such as weapons, axes, knives, and a myriad of other items. Wildlife is also present, such as deer which can be hunted for food, and wolves and bears which are a constant threat to the player as they venture outside.Tools and items degrade over time, forcing the player to make careful decisions regarding their condition and their eventual need for repair. Fire, being a primary component, is necessary for warmth and cooking. The player has to forage for wood and fuel on a regular basis to stay alive. The player can get sick from food poisoning and disease. The Long Dark simulates a full day/night cycle, which is a fundamental part of the game. The game also simulates temperature and wind-chill, encouraging the player to monitor the weather and their clothing carefully at all times to prevent death from exposure. Initially, the game did not feature varied experience modes, but due to player demand, Hinterland added three experience modes to accommodate a range of playstyles, and a fourth mode added later. The easiest mode, "Pilgrim", is for players looking for a more exploratory experience, "Voyageur" is a middle ground and the most well rounded with regard to exploration and survival, "Stalker" offers a more hardcore survival experience, and "Interloper" is for players looking for a punishing, difficult experience.
Added late in 2017, "Custom" lets the player customize many of the gameplay elements to create a unique gameplay experience.
The save game system enforces careful decision making by the player; saving only when the player's avatar enters a building, sleeps, passes time or receives an injury. The only possible ending to the game is player death, with no way to "beat" the game. When the player dies the original save file is deleted, forcing the player to start a new game.