Gaius Baltar regularly uses a well-developed acting talent to spin yarns on virtually any subject when he feels the need.

A charismatic genius and womanizer, he is initially portrayed as a self-serving opportunist, but becomes a braver and more caring character over the course of the series, expressing regret for having been "a profoundly selfish man."

[2] When the Cylons attack the Twelve Colonies of Kobol, they use those backdoors to penetrate software security firewalls, disabling entire fighter squadrons outright and sabotaging vital capital-ship systems.

This woman toys with alternate explanations for her existence, from a Cylon chip in his brain sending signals, to an hallucination created out of guilt over the attacks, and thirdly to her being an Angel sent by God to watch over him, and Baltar finally assumes the latter following a medical checkup and rationalising that her extraordinary information to solve problems cannot simply be his own mind.

Having unintentionally brought about the near-annihilation of the human species, Baltar flees Caprica when Karl Agathon gives up his place on a Raptor, feeling that his own life is less important to save than a famed scientist's.

The Raptor returns to the Battlestar Galactica, where Baltar attempts to endear himself to Laura Roslin, the new President of the remnants of the Twelve Colonies, and hopes to conceal his involvement in the genocide that has taken place.

Both visions acted in similar ways: they were seemingly crueler than the person they were based on and often manipulated the affected party against his or her own species.

Baltar realizes there is a Cylon on board Galactica, but knows he cannot reveal that information, or indicate the device is not a part of the ship without implicating himself in the destruction of the Colonies.

When it is found the evidence is fake, President Roslin holds a press conference publicly exonerating Baltar.

Head Six tells him his public position is now stronger than ever since he has been accused of a serious crime and found innocent, and even possibly been the target of a Cylon plot.

In the episode "Colonial Day", Baltar, now Caprica's representative to the Quorum of Twelve, is elected vice-president with Roslin's support.

In the episode "Home, Part II", Baltar undergoes a brain scan which reveals no sign of a computer chip.

She tells him the first Human/Cylon Hybrid will be born in the ship's brig; soon, the Caprican version of the Cylon Sharon Valerii (pregnant with the human Karl Agathon's child) is imprisoned in it.

He is far behind Roslin in the polls when a habitable planet is accidentally discovered in a region of space where heavy electromagnetic interference makes long-range observation difficult.

After one year, life on New Caprica is extremely difficult, with the civilian population living in rough conditions and shortages of basic supplies like antibiotics persisting.

However, throughout the occupation of New Caprica, Baltar tried to persuade the Cylons their mission to rule over the human race could not succeed and they should leave the planet.

When the Colonials evacuate New Caprica, Baltar and Caprica-Six discover Hera, the child of Sharon "Athena" Agathon whom Head Six predicted would be born in Galactica's Brig.

While the book is not completed at the end of Season 3 (President Roslin confiscates several sections through repeated searches of Baltar's cell), it becomes very popular among certain segments of the fleet populace (despite Roslin's repeated attempts to suppress its distribution), including workers on the tylium refinery ship and Chief Tyrol's flight-deck maintenance crew, as well as his wife Cally Tyrol.

The defense team uses the very end of the trial to try to persuade the jury that Baltar is guilty only of being a scapegoat for the Cylon occupation.

Shortly before the Cylon fleet attacks at the Ionian Nebula, Baltar is led to safety by three female followers of his work, one of whom had asked him to bless her sick child before his trial.

After his following on Galactica is attacked by a polytheism group, Baltar (with the encouragement of his Head Six) disrupts a religious ceremony of one of the polytheist denominations in the fleet.

Shortly after the Baltar situation, Kara Thrace informs President Roslin, whose cancer has returned, that the Cylon Hybrid on the captured rebel Cylon Basestar referred to a "dying leader" learning the "truth of the opera house"—the setting of the dreams Roslin shares with Caprica-Six and Athena.

Although this development distressed Roslin, she decides to bring Baltar with her (along with Karl Agathon—Athena's husband) to the Cylon Basestar to see the Hybrid.

When the Basestar jumps away from the Colonial Fleet, Roslin begins to have a series of visions involving Elosha, a deceased priestess.

The Basestar jumps again and Roslin's vision of Elosha on Galactica culminates in an extended discourse on the need to respect the rights of the living.

Following the discovery of a devastated planet Earth and Admiral Adama's support for a permanent alliance with the rebel Cylons, Zarek and Felix Gaeta lead a mutiny on Galactica.

President Roslin goes to Baltar to ask if she can use his wireless transmitter to speak to the fleet and urge them to support the legitimate government.

They carry her through the ship to the Opera House and enter it to find themselves in Galactica's CIC with the Final Five in similar positions as they were in the vision.

Baltar's speech causes Cavil to falter and finally gives in when Colonel Tigh offers him resurrection in return for Hera and leaving humanity alone for good.

[4] Armando Iannucci praised the show and the characters, particularly "a hugely complicated, pathetic, funny and devious bad guy in Gaius Baltar, one of the most fallible villains ever screened.