Oaths Under God
An oath is a promise made under the witness of God, the most sacred form of promise, and cannot be broken except with the gravest consequences: To Christians, it implies the threat of eternal damnation in Hell.
Perhaps just as important, though, are the more immediate social consequences. All normal people shun oath-breakers. A man's sworn word is one of the few possessions that he has after all material goods are taken away. It measures his soul and personality. A breaker of oaths has a shriveled and tiny soul that is not to be trusted and forfeits the rights that he had as a member of society. Since all of society is based upon oaths and keeping one's word, anyone who fails in this duty fails to uphold society and, therefore, cannot be part of it.
Oaths can be taken literally or figuratively. However, most common people look to the oath's spirit to be fulfilled, while intellectuals sometimes allow only the letter to be fulfilled. Such misunderstandings are the cause of much friction between classes.
In game terms, oaths are handled using the Honor Passion.
Homage and Fealty
Every knight but the king is someone's vassal. Everyone who has a lord has undertaken a ritual (later called a ceremony of commendation) composed of homage and fealty, pledging two free men to an unbreakable, permanent bond of loyalty.
The first part of the ceremony, homage, is ancient, having originated among the Franks and Saxons. Homage is an act of submission. It is the personal oath of an underling to his lord. The vassal kneels and raises his clasped hands to his lord, who encloses them in his own. The vassal gives a brief oath promising aid and counsel. Aid means military assistance, while counsel means support of the lord in his business and the granting of advice. Then the lord gives a similar promise of leadership, and of support expressed as a beneficium, or gift. The beneficium is usually a land grant or fief. After swearing, the vassal rises, and the men embrace to seal the oath. This finishes the act of homage.
Fealty is an oath of faithfulness. It is a solemn oath, often sworn upon saints' relics. Fealty's most common clause includes a promise never to attack the lord. Unlike homage, which can be sworn only once, a fealty oath is sometimes re-sworn to remind someone of his place, or whenever otherwise felt by the lord to be necessary.
After both of these oaths have been sworn, the vassal is the "man of another man." He is also sometimes called "a man of hands and mouth."
Multiple loyalties are possible when a man swears fealty to two (or more) different lords. The issue is confusing at court, but currently, the most popular solution offered to the problem of multiple lords is the practice of having a liege lord. That is, among all of one's lords, one is selected to be liege, and he has priority in the vassal's loyalty in case of conflict.