In the Trinity Universe games, characters bear some degree of allegiance to one faction or another in the setting. Unlike most other White Wolf games such as the World of Darkness or Exalted, these associations aren't inherent or definitive characteristics based on their origin (their "splat"). Instead, one's allegiance reflects one's place in the world, with emphasis on their attitudes towards how to use the abilities that set them aside from the rest of humanity.
Nor is having allegiance to any particular faction mandatory; many characters can and do remain independent for much of — or even the entirety of — their careers. However, independent characters will lack the status or backing that affiliated characters enjoy.
Most psions remain loyal to the order that trained them in the use of psi, but this is hardly a universal maxim. While the six psi orders and the Aeon Trinity are the assumed default options, psions might find themselves more at home working for corporate, governmental or (para)military patrons, or working alongside other, less regimented social or political entities.
The Trinity Players Guide introduces the option of holding membership in two entities at once (specifically, two psi orders). Such "cross-pollination" between orders can have negative social repercussions, at least in the short term, depending on the circumstances in which the character left their initial order and the nature of their employment with their current order.
The most prominent factional divide between allegiances lies between the ostensibly benevolent Project Utopia (including Utopia-aligned factions such as Team Tomorrow and Project Proteus) and the challenges to the Utopian status quo presented by the rogue Aberrants and the nova-supremacist Teragen. However, not all novas are caught up in the conflicts surrounding Utopia; others find their allegiance sketched out by the pursuit of money (Elites, the XWF, the criminal underworld), by other forms of ideology (the Church of Michael Archangel, ReignofEvil.com), or a combination of the two (the Directive). (For a fuller listing of such factions, see the index at Corporate/Government/Other.)
Naturally, one's allegiance can come into flux when tested by conflict; this is illustrated most clearly by the Aberrants, who were nearly all at one point staunchly loyal to the ideals of Project Utopia and were in several cases members of Team Tomorrow. Likewise, as the years wear on and the secret machinations of Proteus are brought to light, many Utopian idealists lose faith in that project and become independent.
The sample allegiances presented in the Adventure! Rulebook are the Æon Society for Gentlemen, the Air Circus, Branch 9, the International Detective Agency, and the Ponatowski Foundation. As with the other Trinity Universe games, these are merely presented as samples, rather than a definitive listing.