(Back cover synopsis):
«Revan: hero, traitor, conqueror, villain, savior.
A Jedi who left Coruscant to defeat Mandalorians — and returned a disciple of the dark side, bent on destroying the Republic. The Jedi Council gave Revan his life back, but the price of redemption was high. His memories have been erased. All that's left are nightmares—and deep, abiding fear.
What exactly happened beyond the Outer Rim? Revan can't quite remember, yet can't entirely forget. Somehow he stumbled across a terrible secret that threatens the very existence of the Republic. With no idea what it is, or how to stop it, Revan may very well fail, for he's never faced a more powerful and diabolic enemy. But only death can stop him from trying.»
“Star Wars: The Old Republic: Revan” continues the story of the legendary Jedi Revan following the events of the video game “Knights of the Old Republic” (KOTOR). Having led wars, fallen to the dark side, and been redeemed after losing his memory, Revan lives as a hero of the Republic. However, fragments of hidden memories emerge, compelling him to investigate a greater threat that could jeopardize the galactic balance.
The novel acts as a narrative bridge between the two "Knights of the Old Republic" (KOTOR) video games and the "The Old Republic" (SWTOR) video game, explaining key decisions made by the protagonist and developing the political and military background of the Sith Empire in the Unknown Regions.
Its full understanding depends largely on prior knowledge of the KOTOR universe, as it establishes a canonical version of the character that could vary in the video game depending on the player's choices.
In other words, this novel is the conclusion to KOTOR; it is set after KOTOR I and KOTOR II. It is also a prequel set three hundred years before SWTOR.
Personally, I've never played KOTOR or SWTOR, and I was able to read it without any problems. That said, I did read some summaries of the video games and watch some explanatory videos. But it's not necessary to understand the novel, although it's helpful to know that it's based on a video game.
It's also the first book in an anthology of novels titled "The Old Republic." They are set around 4000 to 3500 years before the Battle of Yavin (that is, before "Star Wars: Episode IV: A New Hope"). The anthology consists of: Revan, Deceived, Fatal Alliance, and Annihilation.
It is very well written, recommended for Star Wars fans, it has no sexual content, violence abounds, the language is not obscene and there are no ideas contrary to the Church.