The red pill and its opposite, the blue pill, are popular cultural symbols representing the choice between:
The terms, popularized in science fiction culture, are derived from the 1999 film The Matrix. In the film, the main character, Neo, is offered the choice between a red pill and a blue pill. The red pill would allow him to escape from the Matrix and into the real world, therefore living the "truth of reality" even though it is a harsher, more difficult life; the blue pill would lead him to staying in the Matrix, living in a pretend comfortable world.
The Matrix makes references to historical myths and philosophy, including gnosticism, existentialism, and nihilism. The film's premise resembles Plato's Allegory of the cave,René Descartes's skepticism and evil demon, Kant's reflections on the Phenomenon versus the Ding an sich, Zhuangzi's "Zhuangzi dreamed he was a butterfly", the concept of a simulated reality and the brain in a vat thought experiment.
Japanese director Mamoru Oshii's Ghost in the Shell was a strong influence.
In The Matrix, Neo (Keanu Reeves) hears rumors of the Matrix and a mysterious man named Morpheus. Neo spends his nights at his home computer trying to discover the secret of the Matrix and what the Matrix is. Eventually, another hacker, Trinity (Carrie-Anne Moss), introduces Neo to Morpheus.