What is the T Virus in the Resident Evil games? Explained

The source of the zombie outbreak.

Image via Capcom

The T-virus is the source of all the major zombie outbreaks in the original trilogy of Resident Evil games. The virus was developed by the nefarious Umbrella Corporation, and the goal was to use the virus to advance the human race. The virus soon became too much to handle for Umbrella, leading to the Spencer Mansion incident in the first Resident Evil game and the Raccoon City outbreak in the first and second sequels. Origins of the infamous virus and what it does has been well documented within the lore of the Resident Evil games.

Related: What are the PC requirements for Resident Evil 2, 3, and 7’s raytracing update? Answered

Origins of the T-Virus

Screenshot via Capcom

The T-virus is a strain of the Progenitor Virus found in Sonnentreppe, a genus of flowers that can only be located in West Africa. The Progenitor Virus was discovered by the pharmaceuticals company Umbrella in the 1960s, and it was hoping to use the virus to help the company’s ultimate goal of creating a race of superhumans. However, to achieve the necessary funding to create the company’s perfect race, Umbrella made a deal with the military to use the virus to create bio-engineered super weapons and monsters. Most of these experiments to create these bio-weapons happened within the Spencer Mansion.

Concurrently to Umbrella’s creation of bio-weapons, the company was also working on the Wesker Project. The project was to create the perfect human who will be the stepping stone for the human race to ascend. The project led to the death of multiple children, but also led to the birth of the series’ main antagonist Albert Wesker. Eventually, experiments from the Spencer Mansion were bleeding out to the outside world, so Raccoon City sent out its top-tier police force S.T.A.R.S. to investigate. Wesker worked undercover as the leader of S.T.A.R.S., and this lead to the events of the first Resident Evil game. The Raccoon City outbreak would later start because one of Umbrella’s scientists, William Birkin, would contaminate the sewer system of the city with the T-Virus.

What does the T-Virus do?

Dead by Daylight Resident Evil
Screenshot by Gamepur

When affected by the T-Virus, a person receives super strength and unnatural regenerative powers. But it also destroys a person’s mind and causes them to crave human meat. Umbrella’s experimented with the T-Virus on animals, and bio-engineered them to be unholy monstrosities. These monstrosities include a giant snake, giant tarantulas, amphibian monsters, and lickers. The Tyrant program is one of the attempts made by Umbrella to create something with some intelligence — in fact, the “T” in T-Virus even stands for Tyrant. Tyrants are giant humanoid monsters that are one of the most deadly bio-weapons ever created.

Later bosses in the Resident Evil games like Mr. X and Nemesis serve as the successor to the Tyrant program. Whereas Tyrants were mostly mindless, Mr. X and Nemesis showed greater levels of intelligence. The original Progenitor strain of the virus can often have unknown effects on individual humans. Lisa Trevor was a little girl exposed to the original strain and transformed into a towering hunchback that stalked around the Spencer Mansion.

The T-Virus has been experimented with other strains to create new zombie viruses. This includes the more advanced G-Virus, the t-Abyss from Resident Evil Revelations, and the t-Phobos from Resident Evil Revelations 2.