The various metaphysical and magical communities trade with one another in metaphysical goods. In brief, these goods are:
Geases are magically enforced contracts. Break your promise and incur whatever penalties were written in; this usually includes loss of prana. Geases are the instruments by which services are traded between and within the Courts and other groups. Order geases tend to be very long and specific; Chaos ones, the reverse. Those from other quarters have each their own style.
Very high-priced spells, based on ka'u and geases. See here.
For our purposes, karma is a metaphysical influence driving a specific event to happen.
Karma is measured in twists (as in "twists of fate"). To use karma, you must know how to twist it. This is intuitively obvious to all members of the Court of Order, and other metaphysicals can be taught it. You either know the trick of twisting or you don't; there are no dice rolls. In game mechanics, you specify the outcome of actions you cannot otherwise affect and spend one or more twists, plus one psi point for each twist. The outcome is as you specify, unless:
If you fail to get your outcome, you retain the twists and psi points.
Because of the psi cost, training requirements, plus pricing and regulation by Order, karma does not circulate as freely as luck.
An absolutely pure form is, of course, a wholly abstract entity, but you can record one on a smidge of prana so you can carry it around and do things with it. The main thing to do with it is combine it with a suitable amount of force from Chaos, thus producing an actual entity.
Forms for physical objects must be composed in pure ω2, but forms for spells, events, thoughts, and other less tangible things can be composed in ω1 or even ω0. Composing in ω3 or higher would just be pure swank and very difficult, so it hardly ever happens.
Luck is one of Chaos' most popular exports; only the most partizan Courtiers of Order wholly disapprove of it, though rather more Order Courtiers grumble that it shouldn't be used as a substitute for careful planning.
Luck is measured in turns, as in "a turn of luck." To use a turn of luck, make a die roll for something, spend the turn, and then make the die roll again. Use the more favorable of the two rolls.
If you want to try yet again, spend another turn and roll again. Lather, rinse, repeat.
The main purpose of luck is as a hedge against critical failures.
Force, almost the same thing as naked actuality, is Chaos' main export. It's what you fill a form with to get actual entities. Chaos broadcasts it in cosmological amounts into the physical universe, materially aspected, for the use of the Powers That Be, but is happy to provide smaller lots to other customers. These smaller lots are conveniently packaged in sheaths of industrially aspected prana.
If you don't have enough force to fill your form, the results will be unsatisfactory, so make sure to get plenty. Commercially sold force is usually aspected one way or another, so you want to be sure the aspect suits the form. For instance, using force with an inanimate aspect on an animate form will be disappointing; using force with an animate aspect on an inanimate form will be ... confusing.
Courtiers can generate prana (at one point per day) and store indefinite amounts of it, but they cannot give or take psi points while in the physical realm, whether they are manifest or not, and so cannot use psi batteries. However, they can speed regeneration as a learned skill (i.e. part of a trait), and other beings can push and pull psi points for them. These others include Pages and other spiracula, who are not as tightly bound to the Courts.
Previously, the Courtiers were not much interested in the prana trade, since they were able to build up huge reserves of prana. Their Earthly duties required only three or four psi points three or four times a month, the cost shared by 27 Courtiers. That's an average cost of less than half a psi point per month, leaving more than 29 points a month to accumulate over millenia. If a Courtier spent psi on other activities, that was their own affair, but generally they paid no more attention to the prana trade than wealthy aristocrats pay attention to grocery coupons; your exchequer gives an allowance to the cook and meals happen; you don't concern yourself.
The Breakdown beggared them of prana and changed all that. (Courtiers start the campaign with 2d6 points.) So now Courtiers are likely to be interested in the prana trade.
On Earth, prana is typically traded through elixirs, words of power, runes, and geas-bonded bearers. There is also a black market in ghost-drinking and vampirism.