Children of the Glyphs glyphs and worlds
(Background information for the Children of the Glyphs campaign)
The Glyphs are the breath and lifeblood of the Courts of Chaos. It is the mastery of these that has enabled the rulers of the Empire to claim and to hold their dominion. They are symbols that have been infused with power by ritually tying them to a defining aspect of a particular world. A Glyph Wielder draws on the qualities associated with a Glyph by inscribing it on their flesh (by tattooing or scarification, for example). The effects of this depend on both the nature of the Glyph and the nature of the world. Only one Glyph can be drawn from any one world, although it is possible to construct complex designs with multiple effects. Due to the time and effort necessary for such a working, however, it is only worth using the most stable worlds for this.
To use a Glyph, a Wielder must be attuned to the relevant world. Forging such an attunement is part of the process of Glyph creation. Only one person can be attuned to a particular world, and once someone has claimed a world, no one else can use it unless that attunement is broken. An attunement can be broken either by the death of the Glyph Wielder or by changes to the world which significantly alter the Glyphed aspect. This latter fact is why stable worlds are the most prized. The more complex (and powerful) the Glyph, the easier the attunement is to break. (Once a person's attunement has been broken, it is possible for them to forge another one to that same world, although the new Glyph will not be the same as the previous one.)
For stable Glyphs, it is necessary to have stable worlds, so these are highly sought after. Unfortunately, there are a strictly finite number of them, and they have all been claimed, either by the Empire (now under the care of the Council) or the Houses. The stability of a world is inversely proportional to the rate of its time flow. That is: stable worlds have a slower time stream than unstable worlds. The worlds at the core of the Empire are the most stable, and are effectively frozen in time, relative to the rest of the Courts. These are the worlds from which the heads of the Great Houses draw their Birthright Glyphs. The further you travel from the centre, the more unstable the worlds become, and the faster time flows. The ones on the very periphery of Chaos change too quickly for any Glyph drawn from them to last long.
(A side note: no one actually lives in the core worlds, or out on the rim. The former are effectively in stasis and the worlds of the latter are too fluid for a base to remain without constant maintenance or remaking. There is a periphery around the stable worlds where the Great Houses keep their estates. Time here moves fast enough so that they can keep up with the game of politics and keep an eye on what their neighbours are doing, but it is stable enough to allow the establishment of a secure home.)
By its very nature, the process of attuning to a world changes a person as it grants them power. For example, a Glyph of Shielding drawn from worlds where rock elementals, insects, or cyber men are the dominant sapients might turn the skin to rock, cause the Wielder to extrude chitinous plates or trigger an infection of nanites which lay down a weave of metal fibres in the skin, respectively. The deeper the attunement, the more powerful the Glyph and the more significant (and more noticeable) the changes.
Too much change can overload the body and warp the mind and soul beyond all recognition, Wielders generally limit the number of deep attunements they forge. (In game terms, the depth of an attunement and the power of the corresponding Glyph are proportional to the number of points you spend on it. You can have a smaller number of more powerful Glyphs, or a larger number of lesser ones. Both approaches have their benefits.)
There are three different classes of Glyphs: Birthright, Custodial and Chaos. Birthright Glyphs are drawn from the fixed worlds at the core of the Empire and are only possessed by a relatively small number of people. They may be inherited from a parent, granted by a House head or bestowed by the Council. (If someone with a Birthright Glyph dies without heirs, the ownership of the relevant world passes back to the House, and the House head may allocate it as they see fit.) Birthright Glyphs are effectively permanent, and provide a suite of abilities along a theme. They are the most powerful and complex type of Glyph, and are the result of centuries (and in some cases, it is rumoured, even millennia) of optimisation. It is almost unheard of for anyone to possess more than one Birthright Glyph.
Custodial Glyphs come from worlds in the circle where the Houses reside. Generally, a person does not own such a world, but has merely been granted the stewardship of it for a time. In return for maintaining it, they gain its Glyph. Unlike the core worlds, these ones will change over time. Even with maintenance, the changes will eventually grow large enough to break the attunement. At such a time, it is common for the world to be passed into the care of someone else. Guardianship of such worlds generally lasts on the order of years to decades. Higher-ranking members of a house may have a few Custodial Glyphs that other, lesser members of the House -- known as Stewards -- hold in trust for them. (It is not uncommon for the Houses or the Council to use the Custodial Glyphs as a test for those they are considering granting a Birthright Glyph to.) As with Birthright Glyphs, Custodial Glyphs may be granted by the Council or the relevant head of House. However, leases may also be allocated by higher-ranking House members. Custodial Glyphs confer a single ability upon the Wielder.
Chaos Glyphs are the least powerful type of Glyph. They come from the unstable worlds of the periphery and generally provide a single minor, temporary ability. No one actually allocates these worlds to anyone. Rather, someone interested in expanding their repertoire simply heads out into the periphery, finds a likely world and attunes to it, creating a Glyph that they can use for as long as the attunement holds (generally on the order of day to weeks). With sufficient skill, it is possible to create Chaos Glyphs "on the fly". Duels fought by this method are not uncommon in the Courts.
A note on the different types of Glyph: if you have a Birthright Glyph, everyone will know that you have it and what it can do. As it's a suite of abilities, however, they won't necessarily know how you're going to use it. Custodial Glyphs are assigned to you, so someone is going to know what you have. It isn't necessarily common knowledge, but neither should you rely on it being a complete secret. Chaos Glyphs, on the other hand, are as secret as you want them to be.