[adapted from the deceased SWtE game]
[funny note: I have had this in my Draft folder for 3 years...]
THE JEWEL OF JUDGMENT:
WHAT IT IS REALLY:
When the Unicorn stole the Eye of the Serpent, they meant Dworkin. Dworkin was "the Eye" of the Serpent Itself. It was a sacred, privileged role, an investiture in magics, and where he was, the Serpent Watched. He spent years with the Serpent in his brain. Having the Pattern has warded that, but he also occasionally gets "ideas" from the Pattern. All the information the Pattern has recorded from those who have walked on it is available to Dworkin...at a price.
The Jewel is actually Dworkin's demon-Heart infused with Pure Order. The "three-dimensional route" is actually more like a pattern of blood vessels. However, the Order, being Pure, is extremely inflexible, affecting the individual who attunes to it significantly. It leaves the one who attunes to it less malleable, more etched into Reality.
HOW IT ACTUALLY WORKS
The attunement is to the energy which makes Dworkin's Heart potent, through the rune which is the Pattern. The reason the Pattern is exactly that (a Pattern) is that it cannot be modified, once written it is forever etching that same design upon Reality. When it was broken (which requires a ritual and sacrifice, not just eraser fluidblood) it began to open entropy from the Abyss (source of demons) into a cancerous effect upon Reality. The Jewel is immune as it contains the unmodified original Pattern. Those attuned are generally resistant.
Drawing upon it infuses Order into the area. The storms are a chaotic effect, left in the wake of Order being Commanded by Will. This is why the Jewel is safest in Amber, better able to be controlled in regards to the thousands of years of Order laid upon it.
Question: Does that bind Dworkin to the character, or the character to Dworkin?
Answer: I think it does neither, just makes the character a little more Demon. Brand wanted this because, like the Fount in the Keep of Four Worlds, it released some of his human limitations.
WHAT CAN THE PLAYERS DO WITH IT?
Well, first of all we need to discuss Corwin's Pattern.
Corwin is an Opener, which is an older magic, and everything Corwin does will be tied into it. Corwin had to be slightly mad to try writing one in the first place. And, mad, he may have Opened things which he did not understand.
Dworkin's Pattern bound itself to Amber. Corwin's Pattern can be considered a magnet, attracting loose pieces of Reality to it, especially that which was worked free in the Patternstorm of repairing Dworkin's Pattern. It will have a limited "program" based off of what Corwin was dreaming as he wrote it. This "program" will develop as more people walk it.
Can anyone create a Pattern using the shiny red rock? No. Corwin is changed in many ways, some of which strengthened him, some of which weakened him. He was a very good example of being able to benefit from not knowing his limits. Can a PC create a Pattern? I'd love to play it out. Will it hurt? Yep.
What can a PC do with the Jewel? They can no longer bind Dworkin to them; the Pattern protects him from that. He can, however, be hurt by injuries done to the Pattern or Jewel. They can draw Order as per their Endurance. This will mean things will take their true forms, lose their compellings and enchantments. (Many, if not all of the effects the Pattern will give something.) Similarly, what is not of Blood (since that is how the Heart was Bound) can be struck with the lightning of the Pattern (poor horse!). With practice, time and space can be manipulated in Amber or any other Shadow. Finally, that which is of the Abyss can be destroyed. It is the ultimate defense against Primal Chaos.
WHERE DID THE SERPENT'S EYE GO, THEN?
Ah, therein lies a story... for another time.