Over the course of a few episodes, different casts of characters join the secret order Candela Obscura and form a circle to investigate several supernatural phenomena, guided by a Lightkeeper.

The series takes place in the Fairelands, a coastal valley found in the country of Hale, which is plagued by several types of magical horrors that bleed in the world through thinnings of The Flare, a boundary that separates the different realms that comprise this universe.

A secret order, Candela Obscura, has dedicated centuries to the study and containment of these phenomena, which are examined by different circles of investigators guided by a Lightkeeper.

[6] The series is divided in chapters, representing various story arcs guided by different game masters and composed by several episodes, which will each feature a distinct investigation.

[4][7] Bailey plays as the medium Arlo Black, Bhimani as the magician Charlotte "Charlie" Eaves, Johnson as the criminal August "Auggie" James, and Daymond as the professor Howard Margrove.

[3] Carazo plays as the medium Marion Collodi, Fazal as Doctor Jinnah Basar, Mulligan as the soldier Sean Finnerty, Ray as the criminal Beatrix Monroe and Willingham as the journalist Nathaniel Trapp.

[12] The third chapter is led by Aabria Iyengar as the game master with Noshir Dalal, Sam Riegel, Gina Darling, Ashly Burch and Liam O'Brien as players.

[15][16] Starke will return as the game master for the Candela Obscura Live one-shot special with Mercer, Bailey, Ray and guest star Khary Payton as players.

[3] The premiere of the second chapter's third episode was delayed one week to accommodate the broadcast of the Critical Role special The Mighty Nein Reunion: Echoes of the Solstice which aired in the Candela Obscura timeslot.

Mercer, who is the Critical Role Dungeon Master and Candela Obscura show's first gamemaster, commented that "as a GM who's grown up on D&D, having a system that requires me to roll pretty much no dice at all allows me to be entirely present with the players.

[29] Polygon reported that the design of Candela Obscura takes "inspiration and some key mechanics from John Harper's beloved heist RPG Blades in the Dark as well as Free League Publishing's Nordic horror game Vaesen".

I also am really excited about the marks and scars system that Rowan and I developed for Candela specifically, which lets the impacts of the damage you take live with you and, quite literally, change you.

[42] McCauley commented that the actual play "anthology's short-form narratives and manageable schedule present a draw to new audiences, especially those previously intimidated by the main show's extensive back catalog.

However, as the series represents the company's foray into game publishing, it has plenty to entice long-time fans invested in the channel's growth beyond the confines of Dungeons & Dragons".

[39] After reviewing the Candela Obscura Quickstart Guide, Chase Carter for Dicebreaker felt "ambivalent" about the game's ability to create a bridge that would allow "the colloquial Critters an avenue into the rich vein of tabletop titles beyond Wizards of the Coast's shadow".

Samantha Nelson wrote in the Polygon review "Critical Role’s Candela Obscura is but a pale shadow of its inspiration, Blades in the Dark" that the Newfaire setting "feels fairly homogeneous", that "the sample sessions play out like fairly bland procedurals", and that overall the game "might make a great way for the Critical Role crew to show off their acting talents, but it doesn’t seem as useful for someone who just wants to run a game at home with their friends.

"[44] Dan Arndt, in a review of the Candela Obscura Core Rulebook for The Fandomentals, commented that his "biggest issue" was the game's "inability to actually create something that feels actually original, and part of that comes down to its failure as a piece of horror" since "horror works when it's being transgressive" and "Candela Obscura is so worried about making sure everyone feels 'safe' at the table, so worried that people won't think it's endorsing any bad actions, that it rips out its own teeth and shows you the gums.

Nelson for Polygon wrote that Candela Obscura "makes vague efforts at exploring themes of social justice with plots involving corruption and police malfeasance, but they are hamstrung by the game’s explicit denial of intersectionality".