The expanding Amberverse from dkap-amber
A communication and transit method developed by Darkstar, and taught, (by him) to Dworkin. Trumps are generally fueled by Pattern, Logrus, or Magic, but it appears that Darkstar has found a different source to fuel cross-reality capable Trumps.
From Nine Princes in Amber:
“[…] the cards, cast by Dworkin, Master of the Line, who had created them in our image, to facilitate communications between members of the royal family. He was the ancient artist to whom space and perspective meant nothing. He had made up the family Trumps, which permitted the willer to touch his brethren wherever they might be. I had a feeling that these had not been used in full accord with their author’s intention.”
From Nine Princes In Amber:
[Corwin] opened the packet and extracted the cards. They were on the order of tarots, with their wands, pentacles, cups, and swords, but the Greater Trumps were quite different. […] They were almost lifelike in appearance, the Greater Trumps ready to step right out through those glistening surfaces. The cards seemed quite cold to [his] touch, and it gave [him] a distinct pleasure to handle them.
The cards were so very cold on [Corwin’s] fingertips that [he] put them down again, though with a certain sense of reluctance at having to relinquish their touch.
The “standard deck” is drawn by Dworkin, and includes most of the Elder Amberites, as well as some number of the younger ones. There is only one standard deck, even though multiple people have it (it’s Math), so new Trumps show up in multiple places simultaneously. The only place Trump in the standard deck is that of the courtyard in Castle Amber, which is currently heavily trapped.
Dworkin has been teaching Hamster Dworkin Trump, so the Hamsterites have been added to the standard deck.
A number of folk have some non-standard trumps as well. Ask them if you want to see them.