A Virtual Intelligence (VI) is a sophisticated program designed to make modern computer systems easier to use. They are not to be confused with artificial intelligences like the geth, as VIs are only utilised to assist the user and process data (although, like AIs, they can still get out of hand). Though they appear to be intelligent, they aren't actually self-aware, just made with clever programming.
Some VIs have 'personality imprints', with their behaviour parameters, speech pattern and appearance based on specific individuals, although it is illegal to make VIs based on currently living people. The quarians were even attempting to make their 'ancestor VIs' (virtual intelligences preserving the wisdom and personality of their ancestors) truly intelligent, to create a kind of virtual immortality, when the geth rebellion put an end to most of their research into synthetic intelligence.
VIs vary greatly depending on how they are deployed. They can handle search queries on the extranet, act as tour guides—as in the case of the Citadel VI, Avina—or manage sophisticated lab and database work, like Mira on Noveria. Both the humans and the elcor make extensive use of VIs in their military endeavours to process status reports, react faster than organics can or—in the case of the elcor—choose instantly between millions of gambits designed for any combat situation.
A lot of armor upgrades use VI enhancements, so the onboard computer can optimise the armor's combat performance or dispense medi-gel to heal the user. The newest biotic implants, the L4 iteration, use VI technology to constantly monitor the biotic's brain waves and adapt the implant's performance to maximise biotic potential.
In certain circumstances, a VI may deviate from its programming due to software errors or malicious tampering; such a VI is referred to as a "rogue VI." A rogue VI is not self-aware, as they lack the software required by an AI to achieve such a state. Instead, a VI going rogue is akin to a software malfunction, causing the VI to fail to carry out its intended function or to interpret its duties in a way that leads to the VI becoming dangerous.
Several notable incidents involving rogue VIs are known to have occurred. A Systems Alliance VI servicing a training facility on Luna went rogue after Alliance scientists attempted to convert it into a "controllable" AI and triggered the facility's weapons and defensive systems. Another incident occurred on Jarrahe Station, where the resident VI engaged a security lockdown that resulted in the deaths of all scientists aboard the station.
- Avina - A general information VI on the Citadel and Nexus
- Mira - A VI at the Peak 15 facility on Noveria
- ExoGeni VI - A VI at the ExoGeni facility on Feros
- Geth VI - A VI created by the geth to study the Reapers
- Liat'Nir - the only known Ancestor VI still in existence
- K - short for Keelah Si'yah, the Andromeda Initiative ark's main VI interface that also comes with secretly installed augmented conversational matrices
- Hannibal - A rogue Systems Alliance VI that took over a training ground on Luna
- Overlord VI - A hybrid VI developed by Cerberus on Aite
- Info Drone ("Glyph") - The Shadow Broker's personal VI
- Vendetta - A Prothean VI stored in a beacon on Thessia
- Victory - A Prothean VI that oversaw a stasis pod facility on Eden Prime
- Vigil - A Prothean VI that oversaw the lab facility on Ilos
- If Shepard asks Bailey about Mouse during Thane's loyalty mission, he will mention that Mouse is selling a "Shepard" VI made after Shepard's death. Bringing this up to Mouse can result in credits or receiving a copy of the VI. Either way, the player does not get to see the "Shepard" VI until Mass Effect 3.