Trump is an independent power, neither a subset of Pattern nor Logrus. It can be learned by any high-Psyche (it requires a 10 Psyche, minimum) person with a particular kind of artistic temprement. Trump artists tend to be people fascinated by form and representation, and almost all had strong visual-arts leanings from a very early age.
Trump is not an ability that one just naturally develops. If you have this power, you had a trainer, or, at the very least, a deck of Trumps to experiment with. Trumps are unknown on the Chaos end of things (though they work perfectly well there), and most Trump artists are clustered around Amber.
Trumps aren't generally any more durable than standard cards. However, they do have a certain resistance to water damage or the like — going to Rebma won't ruin them.
Sense Trump
Cost: 3 pts
Prerequisites: None
Allows: Draw
The first thing that an aspiring Trump artist learns is how to tell if a drawing is a Trump. This ability is simple to activate and requires almost no effort, but is not "always on." Think of it as being like squinting. You can do it whenever you want, at a moment's notice, and without measureable fatiuge, but it's bothersome to do it all the time.
Draw Trump
Cost: 10 pts
Prerequisites: Sense
Allows: Call ID, Sketch
This is the ability to create full fledged Trump drawings. I presume you're familiar with their properties. The time it takes is about four days for a not-terribly-proficient Artist, reduced by Psyche and Trump Artistry skill. This ability includes being able to draw person, place, and object Trumps.
Call ID
Cost: 7 pts
Prerequisites: Draw
Allows: Memory
Yes, it's the most coveted ability in the history of time.
This is the ability to know who's calling you before you decide whether to accept the call or not. If you decide not to accept, they may be able to press through with the contact anyway, but it's much, much easier to defend against a contact that you never accepted in the first place than to cut off one that you started.
You don't need to have a Trump of the caller in order to identify them, but you do need to have met them.
Sketch
Cost: 10 pts
Prerequisites: Draw
Allows: Hide
This is the ability to draw a Trump Sketch, a lesser version of a Trump, through which contact is more difficult and range is shorter. The advantage of a Trump Sketch is that it takes no more than a couple of hours to draw, and potentially quite a bit less. (Dworkin took, in the GM's estimation, perhaps twenty minutes to do each Trump in Corwin's cell, and that was under less-than-ideal working circumstances). It is more skill intensive to do the "shortcuts" involved in a Trump Sketch than to create the full-fledged thing.
Hide
Cost: 5 pts
Prerequisites: Sketch
Allows: Memory, Gateway
This is the ability to make a Trump which does not literally reflect its subject. (This can serve as a trap to unwary users of the Trump, or as a way of hiding a Trump in plain view).
A hidden Trump will have a weaker link to its subject than one which literally reflects the subject's appearance, and will have a correspondingly lesser range and be more difficult to use. Further, hidden Trumps take a great deal more time to create, usually in the order of weeks (most of that is time spent making a drawing, failing to link it, and starting over). The Artist must be very familiar with the subject.
A Hidden trump is stronger, the more closely it represents its target. It would be much easier to create a picture of a silver rose that was actually a Trump to Corwin, than it would be to create a picture of a silver rose that was actually a Trump to Random.
Trump Memory
Cost: 10 pts
Prerequisites: Hide and Call ID
Allows:
This is the ability to use create a mental image of a Trump powerful enoug that you no longer need to use the Trump to make contact with the subject. The Trump in question must be one that you have created, and the memorization process takes at least as long as the initial creation.
As usual, Trump Memory is shorter range and more difficult than real Trumps.
Gateway
Cost: 5 pts
Prerequisites: Hide
Allows:
Anyone might take a small amount of gear, or even one other person, through a Trump. With this ability, however, an Artist can create a rainbow gateway, throughput limited only by size. It is also useful in that the Artist does not need to accompany his guests through the Gate.
It was through this power, not normal Trump use, that the Amberites were able to swiftly move their army to the Courts.
Holding open a Gateway is not as difficult as one might think. Any Amberite worth his salt should be able to manage it for an hour or two, if he does nothing else.