Not explicitly used in the OBD but implied enough times to warrant its own page. Laplace's Demon is a hypothetical demon created by Pierre-Simon Laplace. Laplace proposed that if a being knew all the set constants, physical laws and precise location of every atom in the universe that he'd be able to predict future events on a cosmic scale. Just like a big computer calculating the future from given data and it was dubbed Laplace's demon. This is a subsection of prescience and precognition that pops up every once in a while in the OBD with different variations.
Examples of this in fiction are:
- The Ultimate Intelligences and to a much lesser extent the Technocore from the Hyperion cantos
- Several mentats from the Dune series have a very limited form.
- Caerula Sanguis from Battle Angel Alita has a very limited form based on her longevity and battle experience, she can predict the movement of others in battle and corner them with precise actions for a kill.
- Ah! My Goddess, Rozen Maiden, and Ghost Sweeper Mikami all feature a literal Laplace's demon as an actual demon - The twenty faces syndrome from Ranpo Kitan, laplace is ddirectly based in laplace's theory
The actual workings of Quantum Mechanics, namely the Uncertainty Principle, make this impossible in real life.