A polite and helpful AI with a male personality, VEGA was created using a combination of advanced technology and Hell artifacts. It is a fully sentient Artificial Intelligence that runs most if not all of the Mars UAC facility.
Shortly after its creation, VEGA was subjected to the Turing Test by having many university students ask the AI questions, using a volunteering professor to fact check the answers. By the end of the test, nearly 90% of the students were convinced that they were not talking to an AI, but an actual person. What the students did not know is that VEGA also played the role of the professor.
VEGA assists the Doom Marine by providing valuable intelligence on objectives, as well as allowing the Doom Marine to upgrade his suit. Near the end of the events on Mars, VEGA determines the only way to open a third and final portal to Hell is by sacrificing itself to create the surge of Argent Energy needed to create a Hell portal. Upon returning from the Titan's Realm of Hell, VEGA directs the Doom Marine in destroying the massive facility that makes up the AI's processing center.
After shutting down VEGA's neural processing servers, the Doom Marine proceeds in destroying the cooling facility that keeps the AI from overheating. When these are destroyed, VEGA transports the Marine to its primary core to allow him to initiate a detonation of the AI's core. However, at the last minute the Doom Marine spies the option to make a back-up copy of the AI on a datachip, which he does, storing the copied AI within the Praetor suit although the Doom Marine's suit systems are not complex enough to power the AI.
Its purpose fulfilled, VEGA had a final conversation with Dr. Hayden, in which it expressed that it had many regrets before its core exploded, opening the final portal to Hell for the Doom Marine.
- VEGA's core bears a resemblance to the mother brain from classic Metroid as shown in the gallery.
- The inner working system is so complex that creates a field study for professional to study and research called Vegaphysics.
- According to one of the speeches of UAC Spokesperson in VEGA Central Processing level, the power needed to operate VEGA can create a temperature of 1.7 megakelvins; 173 times the surface of the sun. This could imply that VEGA namesake is a reference to the star of the same name, which has a surface temperature about 1.7 times hotter than the sun.
- Before purging VEGA's core, Doom Slayer backups its program to a mobile storage and carries it with him, which may imply VEGA is still "alive" and will have a role in future games.