The series revolves around the lives of Sarah Connor (portrayed by Lena Headey) and her son John (Thomas Dekker), who work to prevent the creation of Skynet, an artificially intelligent computer system that will eventually launch a nuclear war on humans.

Besides Cromartie, the Connors are also pursued by FBI Special Agent James Ellison, who initially believes Sarah is an insane criminal (based on the events of Terminator 2).

A dying resistance fighter arrives from the future and provides the Connors a list of people relevant to their mission, many of them requiring protection from Terminators.

Meanwhile, Jesse Flores and Riley Dawson have arrived from an altered future where John, as resistance leader, only communicates through Cameron, having become increasingly reliant on her.

In the season-one finale, Cameron is damaged in a vehicle explosion which has negative effects on her programming throughout the second season, occasionally causing her to glitch and engage in unexpected behavior.

Accordingly, he chose not to direct any other pilots for the rest of the television season, focusing solely on the Terminator project in order to protect "the integrity of what Cameron created.

[15] Dekker chose to initially portray John as weak and then gradually build him up into a stronger character, progressively transforming him into a believable future savior of humanity.

Green was primarily known for his role in Beverly Hills, 90210, a 1990s teen drama series, prompting uncertainty about whether he was miscast in The Sarah Connor Chronicles.

[59] The series premiered as the strike was still underway, and Friedman used his spare time to read online comments, gaining insight for future episodes.

Much of the cut material related to John and Cameron's time in high school, deemed unimportant compared with scenes involving Sarah.

Friedman said producing the series on such a budget was difficult, but that it also occasionally worked in the show's favor as it "left us doing things that were more dramatic and emotional and conceptual, sometimes".

[11] A primary filming location was the backlot of Warner Brothers Studios in Burbank, California, on a set previously used by Gilmore Girls to depict the fictional town Stars Hollow.

For financial reasons, the main theme of the Terminator film series, originally composed by Brad Fiedel, is featured only briefly in the TV series—mainly during the title sequence.

[88] John's theme was originally composed for a specific scene in the pilot episode and performed with a solo clarinet to convey his loneliness and awkwardness.

[95] Fox began their advertising campaign for Terminator: The Sarah Connor Chronicles on September 27, 2007, with a brief teaser which ran during primetime programs, consisting of an image of two red dots that lasted for a few seconds on screen before disappearing.

Other forms of advertisements used included: mobile tours on "Terminator" buses sponsored by Verizon Wireless; an interactive cell phone game based on the series offered by Verizon's V CAST, which rewarded the players with ring tones, wallpapers and behind-the-scenes footage; cable tie-ins; online outreach via the official website and wiki; online sneak peeks; and a poster design contest run by Fox.

[96] Advance screenings of the pilot episode were also held at the 2007 Comic-Con International convention and at Golden Apple Comics in Los Angeles on January 4, 2008.

[99] Billboard advertisements, which were described by Variety to have "blanketed New York and L.A.", contained images of Summer Glau's Terminator in a "Lady Godiva-esque pose" used to target the young-male demographic, while the key art emphasized on Sarah Connor being at the core of the show to attract the "mom demo".

"[100] Originally scheduled to premiere on Monday, January 14, 2008, the show's debut was rescheduled to commence a day earlier, after Fox reorganized their broadcast timetable due to the writers' strike.

Benjamin Svetkey of Entertainment Weekly was critical of the hiatus: "Just figuring out when new episodes would be on the air has been a time-travel paradox so perplexing it would drive John Connor crazy.

[135] Friedman has declined to reveal how the storyline would have proceeded and asked his fellow writers to follow suit, instead letting fans decide the outcome for themselves using their imagination.

[150] Robert Bianco of USA Today gave the premiere episode four and a half stars out of five, calling the series "smart, tough and entertaining".

[152] The Los Angeles Times declared the show "has heart and feeling" and "an almost Shakespearean exploration of fate vs. character" that features "plenty of really great fight scenes, and explosions, as well as neat devices developed in the future and jury-rigged in the present".

[153] Film industry journal Daily Variety declared the series pilot "a slick brand extension off this profitable assembly line" that showcases "impressive and abundant action with realistic visual effects and, frankly, plenty of eye candy between Glau and Headey".

[154] At the start of the second season, Variety praised "Headey's gritty performance as Sarah—managing to be smart, resourceful and tough, yet melancholy and vulnerable as well" and wrote that "'The Sarah Connor Chronicles' continue to deliver", getting "considerable mileage out of the constant peril" facing the characters.

[155] The Connecticut Post placed it on its list of the top 10 TV shows of 2008: "It's smart, with thought-provoking meditations on parenthood, destiny and human nature, and features good performances by Lena Headey, as Sarah, and Summer Glau.

Though limited to his viewing of the first two episodes, Goodman leveled criticism against Fox for having "taken the wholly predictable course of putting a lot of money into explosions and regenerating cyborgs" but not having "paid much attention to plot, casting or writing".

[158] In his review of the second season, Travis Fickett at IGN felt despite a few middling episodes and the restrictions of a TV budget, "[the series] turned out to be intelligent, complex and consistently operated on a deeper emotional level than anyone could have expected.

[168] Zaki Hasan, writing for the San Francisco Chronicle in 2019, called the series "one of the franchise's most fascinating forays — one whose announcement was greeted with a fair amount of skepticism but ended up working a lot better than many would have expected".

Hasan went on to call the show "unfairly forgotten by many, but also ripe for rediscovery for the many ways it redefined what to expect from the brand while still remaining tonally consistent with the films at their best".