|d20 Modern System Reference Document|
The allegiances system is optional.
A character may have up to three allegiances, listed in order from most improtant to least important. These allegiances are indications of what the character values in life, and may encompass people, organizations, or ideals. A character may have no allegiances (being either a free spirit or a lone wolf) or may change allegiances as he or she goes through life. Also, just because the character fits into a certain category of people doesn't mean the character has to have that category as an allegiance.
If the character acts in a way that is detrimental to his or her allegiance, the GM may choose to strip the character of that allegiance (and all its benefits) and assign an allegiance more suitable to those actions.
A hero's allegiance can take the form of loyalty to a person, to an organization, to a belief system, to a nation, or to an ethical or moral philosophy. In general, a character can discard an allegiance at any time, but may only gain a new allegiance after attaining a new level.
Having an allegiance implies having sufficient intelligence and wisdom to make a moral or ethical choice. As a result, a character must have Intelligence and Wisdom scores of 3 or higher in order to select allegiances.
Allegiances include, but are not limited to, the following examples.
Person or Group: This includes a leader or superior, a family, a group of linked individuals (such as a band of adventurers or a cell of secret agents), or a discrete unit within a larger organization (such as members of the character's squad or platoon, or individuals whose safety the character is responsible for).
Organization: This may be a company or corporation, a gathering of like-minded individuals, a fraternal brotherhood, a secret society, a branch of the armed forces, a local, state, or national government, a university, an employer, or an otherwise established authority.
Nation: This may or may not be the nation that the hero currently resides in. It may be where the individual was born, or where the hero resides after emigrating to a new home.
Belief System: This is usually a particular faith or religion, but can also be a specific philosophy or school of thought. Belief systems could also include political beliefs or philosophical outlooks.
Ethical Philosophy: This describes how one feels about order, as represented by law and chaos. An individual with a lawful outlook tends to tell the truth, keep his or her word, respect authority, and honor tradition, and he or she expects others to do likewise. An individual with a chaotic outlook tends to follow his or her instincts and whims, favor new ideas and experiences, and behave in a subjective and open manner in dealings with others.
Moral Philosophy: This describes one's attitude toward others, as represented by good and evil. An individual with a good allegiance tends to protect innocent life. This belief implies altruism, respect for life, and a concern for the dignity of other creatures. An evil allegiance shows a willingness to hurt, oppress, and kill others, and to debase or destroy innocent life.