The Three-Body Problem is not a series. The Three-Body Problem is the title of a science fiction novel by Chinese author Liu Cixin. It was first published in 2008 and has been translated into English and several other languages. The Three-Body Problem is part of the Remembrance of Earth's Past trilogy, but it is not considered a series.
The plot of the novel follows a complex plot of physics, philosophy, and politics, as three characters work to unravel the mystery of an alien race's attempts to invade Earth. The novel has been immensely popular, and as a result, spawned two sequels, The Dark Forrest and Death's End. However, these novels are not considered to be part of a series – instead, they are part of the same overarching plot.
In 2020, the novel was adapted into a Netflix original series called The Three-Body Problem. The series follows the plot of the novel and the plot of the sequels, but unlike a novel-series, the characters are played by actors.
Overall, The Three-Body Problem is not a series. It is a novel, part of a trilogy of novels, which was also adapted into a Netflix series in 2020.
