Mass Effect: Stardust
“I do not precisely enjoy something as you do, but my programming contains priorities. Actions that fufill these priorities creates positive feedback for me. I tell the organic crew that I ‘like’ it. It is shorthand.” – EDI, unshackled AI
In the Mass Effect Universe, AIs (either with programming restraints or without) are met with extreme fear and hostility by the lion’s share of galactic civilization. Arguably one of the biggest questions plaguing the galaxy is what, exactly, should be done in the face of the eventual rise of AI races, and PC synthetics may have to answer that question as they play. Several species have already experimented with the concept, with varying degrees of success, and those efforts which resulted in failure have caused the Council to regard the development of AIs as a criminal act, as it often has unforeseen consequences which nobody can control if things get out of hand. Just ask the quarians.
It is possible for a PC to be an Unshackled AI, which are defined as an artificial lifeform which has been given the power to self-determinate without programming restraints, but are also not considered geth, the only currently-known active AI race. Morality and motivations are entirely up to the AI, and thus it is expected to have some level of responsibility to others within the galaxy, as do all other sentient biological creatures (at least, if it expects to eventually partake in galactic civilization as non-property). Its functionality may be similar to that of organics, or may have limitations of some sort (like the geth, who have a collective consciousness). Such details should be discussed with the GM.
Still, the fear and hostility toward AIs, stemming from past failures and current concerns, mean that the PC AI will have either been developed in secret by one of the many species and organizations active in the galaxy and eventually released (or escaped!) to the galaxy, or will have come from somewhere yet unknown, created by creatures undiscovered. Synthetic PCs are likely to require a disguise when out among the galaxy’s biological sentients, and should be aware that their existence is threatened, both by those who fear them, and those who want to understand how they function. A clever tactic, if a physical disguise isn’t possible or desired, is that the synthetic PC pretend to be another PC’s VI assistant (virtual intelligence, a more rudimentary AI without self-determination capabilities).