This is a quick primer on creating a Nobilis character. Many concepts will not be explained in detail, and the rulebook has copious examples, so this should not be considered a replacement for the rulebook.
Remember that you should start with a concept. Most Nobles were ordinary mortals before they were chosen by an Imperator to become one of his Powers. In many ways, a Noble is forced to leave his mortal life behind, but this isn't always easy.
Every PC gets 25 character points to buy Attributes with. (In addition to Attributes, there are also Gifts and extra Miracle Points to spend character points on, but most if not all of your points usually go towards Attributes.)
There are four Attributes, each one ranked from 0 to 5. (Imperators can have Attributes above 5, but Nobles cannot.) You start at 0 in each Attribute, and each extra point costs 3 points. There is no "average" Attribute for Nobles; they range all over the map.
See the Summary Page for appropriate charts, and also a list of the costs for performing various Noble miracles.
Aspect governs your physical and mental abilities. Anything your character does that is not supernatural is governed by Aspect (although high levels of Aspect will allow you to accomplish feats so miraculous they may as well be supernatural).
This is the power you have over your Estate. It is separate from the power of the Estate itself; one could have a very important Estate (like Death) but little power over it, or a minor Estate (like Feathers) with which you can perform incredible miracles (like causing it to rain feathers made of gold all over the world).
Your own Estate is your Primary Domain. You may also optionally buy levels of Domain for one or more secondary Estates, related to your primary Estate. Domain over your primary Estate costs 3 points per level. Secondary Domains costs 1 point per level, and cannot exceed your primary Domain level.
Example: The Power of Computers buys 3 levels of Domain (9 points). He decides that his Estate also encompasses Algorithms at level 2 (2 points). Total cost is 11 points.
Realm measures your rank (and power) within your Imperator's Chancel. Since a lot of game-time will be spent in your Chancel, this can be very important. Realm allows you to perform miracles within your chancel much like Domain allows you to perform miracles with your Estate. Also, the higher your Realm, the more say you (as a player) have in the creation of your group's Chancel. Realm also governs somewhat how much other Nobles will respect you in.
Spirit is a measure of the strength of a Noble's "soul," or how much of his Imperator's shard is imbedded within him. It provides defense against Noble miracles -- each level of Spirit acts as a shield against any supernatural powers directed against you. Spirit also allows a Noble to work miracles through one of his anchors (see below). A Noble may have a number of Anchors equal to his Spirit level +1.
Gifts are permanent supernatural abilities a Noble might have. Immortality, shapechanging, the ability to perform a particular type of miracle at will, the ability to walk between worlds, etc. Many sample Gifts are described in the Nobilis rulebook. A summary of Gift costs is on the Summary page.
Starting PCs get 5 Miracle Points in each category (Aspect, Domain, Realm, and Spirit). You can buy extra Miracle Points (of any of the four types) for 1 point each.
Anchors are mortals with whom a Noble has bonded. In order to bond to an Anchor, you must either love or hate him. A Noble can see through the eyes of his Anchor(s) at will, and can even transfer consciousness into an Anchor's body or (with difficulty) work miracles through the Anchor. This allows Nobles to be in more than one place at the same time. Anchors are (NPC) characters in their own right, and while a Noble can always force obedience from his Anchors, they are not necessarily loyal to their Noble.
You can have a number of Anchors equal to your Spirit rank +1. Choosing your Anchors is part of character creation.
Things that are important to a Noble represent vulnerabilities, things that another Noble or an Execrucian can defile (and thereby steal Miracle Points). These things are called Bonds; most Nobles try hard to keep their Bonds secret and/or protected. Each PC must divide 20 points among his various Bonds, indicating how important each thing is to him. Bonds can be people, places, particular items, goals, concepts, ideals, etc.
Example: The Power of Serial Killers' Bonds:
Rival Powers and Execrucians can defile a Bond by using the Nettle Rite. For example, the Power of Serial Killers' reputation could be defiled by putting his body count in doubt (claiming that the victims died of natural causes, or didn't actually exist), etc.
Handicaps are limitations on a character. (These include Virtues and Affiliations, but they are described separately below.) Handicaps in Nobilis do not give extra character points. Rather, a handicap is worth a certain number of bonus Miracle Points.
There are two kinds of Handicaps: Limits and Restrictions. A Limit is a permanent disadvantage for a character, something that limits the character's ability to use his Attributes. Limits provide a certain number of bonus Miracle Points at the end of each adventure, when characters regenerate their Miracle Points.
View sample Limits.
Restrictions are disadvantages that only affect characters in certain circumstances (a vulnerability, certain things his powers are not able to affect, cannot cross running water, someone has blackmail information on him, cannot lie, etc.). A Restriction gives the character some extra Miracle Points (immediately) if it causes the character a serious problem during play. For example, if you have a Restriction Hated by Animals (worth 1 Miracle Point), you get an extra MP whenever during the story you are threatened by a hostile beast capable of posing a threat (or at least a serious inconvenience) to you.
Virtues are optional. Not all Nobles have one, and very, very few have more than one (special permission from the GM required).
A Virtue is some character trait that is a fundamental part of the character's soul. It largely defines the character's personality. Examples: Honest, Cruel, Greedy, Lecherous, Careful, Peaceful, Secretive, etc.
Nothing can compel or trick a Noble to act against a Virtue. You can't make an Honest Noble lie or provoke a Peaceful Noble to violence. Nobles have a natural ability to sense the most "virtuous" course of action in any situation. Cruel Nobles always know exactly how to cause the most pain, Careful Nobles always know the safest and most prudent course of action, etc. If a Virtue gets you into serious trouble (not merely an inconvenience that you can work around, but something really bad an Honest Noble brought before the Locust Court to plead on charges of loving an Anchor, or a Lecherous Noble given responsibility for escorting an allied Imperator's virginal, hot-to-trot bride to her wedding...), then you gain an extra MP. Virtues must be roleplayed, of course.
Every Noble must have an Affiliation, a personal code by which he lives. Affiliations are somewhat like religions to the Nobilis; they define what the Power's values and ideals are. Most Nobles choose the Code of their Imperator's Affiliation; they can have different Affiliations, though opposing ones can cause friction. A Noble chooses his Affiliation (or some say it is chosen for him) at the moment of his Ennobling; upon receiving his Imperator's soul-shard, he suddenly experiences a moment of clarity in which his purpose in life is revealed to him. Whether this is really free will or imposed on him by the Imperator or other forces is a matter of debate. As a general rule, it's not possible to change an Affiliation.
Great service to your Affiliation, by doing something that advances your ideals, will grant a bonus Miracle Point. Betraying your Code will cause the loss of a MP. Most Nobles subscribe to one of the follow codes:
Some Nobles have their own personal Codes. Imperators who are True Gods or Aaron's Serpents also each have their own individual Codes, which their Nobles frequently adopt. Keep in mind that while each Code is summarized by its three most essential principles, these three statements do not define an Affiliation any more than "(1) Accept Jesus as Lord and Savoir, (2) Obey the Ten Commandments, and (3) Serve God" defines Christianity. A PC who wishes to define his own Code must describe his philosophy and the basis for it in detail, not just provide three summary statements.