In 2020, Frictional Games released the source code for Amnesia under a GPL license. If you are a developer looking to "generate" a new piece of the engine or a Total Conversion mod, this is your best starting point.
The community on the Amnesia Wiki provides extensive guides on scripting (using HPS files) and level design. 3. Accessing the Source Code File: Amnesia.The.Dark.Descent.v1.41b.zip ...
Launch the game and select "Custom Stories" from the main menu. 2. Creating Your Own Content If you want to generate/create your own custom story: In 2020, Frictional Games released the source code