Following the previous installment, Sierra opted to render the third game in the series in 3D graphics, with a heightened level of puzzle solving and exploration.

Although Jensen had approved of the actor who portrayed Gabriel in the last game, it was decided that Curry should return, owing to her belief he provided the right personality for the character.

As with Sierra games of the time, a running score is used to keep check on actions, both required and optional, that players have completed (i.e. acquiring an object needed for a puzzle).

Interactive objects are highlighted when the cursor is moved over them, to which doing so activates an action bar of "verb" commands that can be conducted by the player.

To combat those who use such forces for evil against humanity are the "Schattenjägers" – a German translation of the words "Shadow Hunters" – who take it upon themselves to defend the innocent from such beings; their origins, however, are shrouded in mystery.

The game's story is inspired by a 1950s conspiracy theory concerning 19th-century parish priest Bérenger Saunière and a secret treasure he hid away around the village of Rennes-le-Château in southern France, incorporating several elements concerning the mythology of vampires and the Holy Grail, the myths surrounding the Knights Templar, and the religious stories of Jesus Christ before and during his crucifixion.

Other supporting characters feature the voices of Philippe Bergeron, Rene Auberjonois, Susan Silo, Karen Ross, and Tom Kane.

When seeking coffee in the hotel, Gabriel learns that the night he arrived, a treasure hunting group arrived at the same time, including: Madeline Buthard, the tour's leader; Vittorio Buccheilli, an Italian tourist; John Wilkes, an Australian treasure hunter; Emilio Baza, a Middle Eastern tourist; and Frank Mosely, Gabriel's police detective friend from New Orleans.

That evening, after Grace arrives with James' men, Gabriel tails his replacements, and witness them interrogate Arnaud roughly, while greeting Larry with an odd handshake; Frank later reveals it to be Masonic.

After a visit to a local winery, owned by Excelsior Montreaux, she and the group come across the bodies of James' men, both of whom were brutally murdered and drained of their blood.

Upon hearing of this, Gabriel questions the group, and examines the crime scene with Frank; the visit sees him experience visions of the murder, determining the killers were vampires.

Talking with Grace regarding their suspects, she suggests to him to visit Montreaux, after finding his winery to be deeply unsettling for unknown reasons.

Grace accepts, and discovers he found a hollow chamber under the valley through seismological surveys; unfortunately, she is forced to leave him in his room when he makes a drunken pass at her.

Suspecting Mosely took it and discovering Prince James has turned up, Gabriel decides to question his friend and asks Grace to track it down.

Alluding to an infamous puzzle early in the game in which Knight must use tape to get hair from a cat and use it to make a fake mustache, Bilas recalled: "It was terrible!

[4] Though she was satisfied by Dean Erickson's performance in the previous game, Jensen felt that Tim Curry represented the real voice of Gabriel Knight and opted to have him return to the role.

In every Gabriel Knight game, the popular gospel hymn "When the Saints Go Marching In" can be heard, albeit in different remixes and forms.

At the same time, he criticized Tim Curry's voice-over, as "a cold and over-exaggerated interpretation of the southern accent", and the switch to 3D which they felt "is not yet ready to depict the emotions and feelings in the way actors can".

[16] Erik Wolpaw of GameSpot shared the sentiments about Curry's "terrible acting job", calling the "fake accent and overly dramatic delivery [...] almost unbearable".

"[17] In May 2000, Jane Jensen remarked that the "sales of Gabriel Knight 3 were not sufficient to offset the cost of development given that we had to build a new engine.

Even in the fight between two first-person shooters with adventure leanings, the simpler of the two (Half-Life) won out over the more imaginative (System Shock 2).

Cliff Hicks made a point about the vanishing adventure genre: "There's no way to beat this one, we're afraid, and we don't think we'll see these games make a return, not for a long time, anyway.

"[31] A month later, Erik Wolpaw of Old Man Murray used Gabriel Knight 3 and its "Mosely disguise" puzzle as an "alternate theory of who killed adventure gaming".