In Amnesia: The Dark Descent, the player takes on the role of Daniel, an amnesiac man trapped in the mansion of a Prussian Baron named Alexander. The only clues to Daniel’s true identity are mementos and notes left behind by Daniel himself, who reminds himself to find and kill Alexander. Gameplay has the player searching for Daniel’s diaries and other notes and journals of the poor souls who have crossed Baron Alexander. The player must solve the mystery of the mansion while running from a Shadow that is constantly chasing the player throughout the game.
The game takes place from a first person perspective, however there are no weapons. Daniel cannot fight monsters and the only choice is to run or hide. Along with self-preservation, the players must keep the hero sane. In order to stay sane, he must keep moving and pushing the plot forward, as well as making sure there is always light. It is often necessary to scour every corner for oil and tinderboxes. Oil will allow Daniel to use a lamp to provide it with light and tinderboxes can be used to light candles and torches strewn throughout the mansion. If Daniel remains in the dark for too long,he will gradually lose his sanity. As Daniel loses sanity, the world will distort and become hard to navigate and will gradually fall apart and the Shadow will find the player. The player must evade the shadow entirely, but this will affect Daniel’s sanity as to hide from the shadow, the player must also hide in the dark. The player must also never look at the Shadow because if Daniel stares at it too long, his sanity will be fully compromised and the shadow will find the player and take a deadly physical form.
The player must solve various puzzles and the game is very much a fully interactive adventure game. Interaction with the environment is performed by using a physics based method where the mouse is emulated as a hand, meaning the player will need to rotate it to turn wheels or use it to grab drawers and pull them open by moving the mouse. It is also possible to pick up objects and throw them to distract the shadow or solve certain physical puzzles.