Theory of the Dream
Every now and then, a large number of creatures and beings "leave" their home world or plane - what, where and whenever this might be - to gather in a special place: The Dream.
Each Dream event represents a gathering at a moment favorable to the arrival of a large amount of Dreamers in the Dream world. In between each gathering, approximately one year passes in the Dream - including all the possible consequences.
In order to travel into the Dream, the dreamer's conscience has to leave the body in their home world and "dream" his presence in the Dream world.
In terms of definitions, speaking about "the Dreamer" means speaking about the creature dreaming and physically existing – asleep, in meditation, unconscious - in his home world. When speaking about "the Avatar", one speaks about the representation, or the picture, of the Dreamer within the Dream - a being made of dream energy.
This has many consequences! Obviously, the Avatars do not need to have the same properties and appearances than the Dreamers. A human can be a dragon in the Dream and vice-versa. A Dreamer who is a god in his home plane will not be a god in the Dream. He will be subject to limitations, which are enforced by the physics and the axioms of the Dream.
This also means that the Dream is made of dream energy and that it is not physical. Its form and appearance seem to be defined by the subconsciousness of the collective of Dreamers and it also seems that the way the Dream currently "is" (a fantastic medieval world), is the way that the Dreamers wanted the Dream to be.
Most of the dreamers dream only during the time of the gathering and return to their respective reality afterwards by waking up. However, it is possible for some dreamers to stay in the Dream. Outside of the Dream, one year passes as well.
Rules and Powers
There are rules (often named axioms) within the Dream and within these rules, Avatars have the freedom to move and act. Expanding on the theories discussed above, there might be possibilities to "bend" these rules and even modify them permanently. Beside these axioms, there exist immutable Concepts within the Dream, which are instated to ensure a progression of the Dream, avoiding stagnation.
Some Avatars are able to produce effects like terrorising, paralysing and enchanting weapons with special properties. These capacities are nothing else than the possibility of using Mana, dream energy, to form and shape the Dream.
But there is more! Creatures and beings that have a stronger capacity of shaping the Dream also exist in the Dream world. They are able to achieve things that an Avatar cannot even imagine. Some of these beings, the obvious ones, are Entities, The Pythia or the Mage-Dragon.
Rituals and Bending the Axioms of the Dream
But there is even more to it! Since The Dream is after all what the collective of Dreamers dream, why should it not be possible to influence the Dream by focusing willpower and dream energy? That is what Rituals are about.
Rituals are ceremonies performed by a group of Avatars to focus their will power, and by this their dream energy, on a common goal in order to shape the fabric of the Dream. The more focus that is achieved, the stronger the effect will be. It is even possible to definitively alter the axioms of the Dream. Examples of such powerful Rituals can be found in the Saga of the Dream.
However, some competences are required to conduct rituals. Not every Avatar is able to control and direct the huge focus energy of a group of Avatars. It is also possible to increase the focus of a ritual by "artificial" means.
Rituals are not necessarily religious or magic. Any type of focusing ceremony does the job. A ritual can be a religious sanctification, a dark sacrifice, a magic séance, a scientific experience or the construction of an invention. The important thing is to create a high level of dream energy bundled to one single will.
The Dream Yarn, Dying and Waking-up
When becoming conscious within the Dream, all Avatars are wearing a Dream Yarn. It symbolises their link to the Dream, their dream energy, and the loss results in an immediate dematerialisation of the Avatars and its re-materialisation within the Limbus. The Limbus is the only place where an Avatar without Dream Yarn is able to "be".
Bringing an Avatar's life to zero just makes him lose consciousness, but removing his Dream Yarn when he is in "coma" has the effect described above. Obviously, the body cannot be looted, healed or otherwise misused after the dematerialisation by virtue of the Dream Yarn's removal. The Avatar is simply not there anymore!
Losing the Dream Yarn in any way is the equivalent of "dying" in the Dream. However, after passage via the Limbus, the Dreamer can continue his Dream. Yet the Dreamer is likely to become (or "have") a nightmare before goes back into his own Avatar.
A "Wake-up" is a different case! Waking-up an Avatar means to violently eject him from the Dream world. As a consequence, he physically awakes in a violent manner on his home world, preventing him to ever come back to the Dream world again. Awakening is de facto the permanent removal of an Avatar from the Dream! It requires a considerable amount of dream energy as well as the knowledge on how to use this energy.