Dr. Eli Vance was a physicist and researcher, apparently in his late fifties or early sixties with short gray hair, a beard, and a mustache. He wore a prosthetic leg to replace his left leg beneath the knees.
He is also the father of Alyx Vance and one of the main characters from Half-Life 2 and its episodes. He will appear in the prequel virtual reality game Half-Life: Alyx, which takes place in-between the events of Half-Life and Half-Life 2.
He was voiced by the late Robert Guillaume in Half-Life 2 and it's episodes, and James Moses Black in the interquel game Half-Life: Alyx.
Eli is warm, good-humored, and charismatic, holding everyone around him in the aura of his personal charm. A skilled scientist, he designed the Gravity Gun and Dog, "put together" the Shorepoint Scout Car with his daughter (adding the Tau Cannon to it himself), and was able to rebuild a teleport with the aid of the other key Resistance Members. Eli may also have had previous experience with a melee weapon, seeing that his fight against the Combine Advisor did some damage. But, it was futile, seeing as the Advisor plunged its "tongue" into the back of Eli's neck, killing him.
By 200-, Vance is employed at the Black Mesa Research Facility, working in Sector C's Anomalous Materials. As a full-time employee of Black Mesa, he lives in the facility itself with his wife Azian and their young daughter Alyx.
Although he was never named during the game or featured as a full character, he is seen on two occasions. First, when Gordon Freeman is making his way into the test chamber: Dr. Vance and another scientist voice their concerns that their computer equipment is being damaged due to the heightened strains of the morning's experiment. Second, when Gordon retraces his steps through Sector C after the Resonance Cascade, he encounters Vance and the scientist he had been with earlier, who is now badly injured. Vance informs Gordon that the telephone network has broken, and sends him up to the surface to seek help. His last act in Half-Life is to operate the retinal scanner that starts Gordon on his long quest through the facility.
Eli somehow managed to escape the facility along with his daughter Alyx, however lost his wife Azian.
A decade following the Black Mesa Incident, Eli and Alyx are transferred to the Combine city of City 17, where they begin to build up a resistance against the alien oppressors. At some point Eli is captured by the Combine, leading Alyx on a mission to try and save her father, among other undisclosed goals.
Two decades following the Black Mesa Incident, Eli, along with former Black Mesa colleagues and his daughter Alyx, lead the resistance against the Combine. At this point Eli is residing at a resistance base by the canals, named Black Mesa East, and is working on teleportation technology. Alyx is teleported to Black Mesa East from Dr. Kleiner's lab in City 17 to Black Mesa East, and although Freeman (who has just returned after a twenty year absence) attempts to follow through the portal, an accident involving Kleiner's pet headcrab Lamarr causes Freeman to be trapped in City 17, and having to make his way to Black Mesa East on foot.
After Freeman arrives at Black Mesa East, he is greeted by Eli, and gets acquainted with his assistant Judith Mossman, whom Alyx has negative feelings towards. Shortly after Freeman's arrival, the Combine infiltrate Black Mesa East and capture Eli, and Freeman and Alyx are separated in the chaos, forcing the pair to takes separate paths. Alyx later communicates with Freeman via radio, and informs him on her father's capture and asks Freeman to head to the super-prison Nova Prospekt, which is under the control of the Combine.
- Harry S Robins (the main voice actor for Isaac Kleiner voiced Eli among the other random scientists during the original Half-Life.