The Long Dark is a first person, single player survival game set in a snow covered Northern wilderness. The game is a purely sandbox experience without story elements. The player instead simply lands in the middle of a desolate snow covered rural area completely alone, and is expected to immediately start battling the elements in order to survive.

In its sandbox form, this is a perma-death game with no win condition that isn't externally motivated (by leaderboards or achievements). A small number of challenges can be chosen at the start of the game to add more specific objectives and win conditions to the gameplay.

The main gameplay consists of exploring the five interconnected maps of the game world in search of shelter, equipment and resources, while managing the character's basic needs (hunger, thirst, body temperature, fatigue, encumbrance, health) and avoiding dangerous animals. These game maps are persistent, however the available equipment that spawns in them is randomized.

There is no character creation, but there is a skill system that levels up by use and improves the player's efficiency at different tasks. One can harvest wood and plants, fish, hunt, manage their inventory and craft items (tools, food and medication). Most equipment and clothes can also be repaired through the crafting system, provided one has the necessary resources and tools available.

With a day-night system, dynamic weather and an animal AI that tries to simulate real behaviour, the game attempts to mimic a survival experience in a natural environment with some degree of realism. However the amount of available wildlife is limited: One can trap rabbits, hunt deer, and hunt or be hunted by wolves and bears. The dangerous animals can be fought off through a rudimentary combat system (melee or ranged), avoided through a basic stealth (line of sight) system or distracted/scared away with flares. Hunting is done with a bow, pistol or rifle, the latter two being dependent on finding some of the limited available ammunition.

The relatively low amount of dangerous enemies, slow pace and emphasis on atmosphere and exploration of the game mean that The Long Dark differentiates itself from the majority of survival games of its era by pitting the player against nothing but a hostile natural environment.