This was the last book published before the announcement of third edition, and I think it deserves at least a whole star for being the book that does the most to expand the scope of the world since...well, since Scavenger Sons. One of the problems with Exalted as a whole is that the setting was laid out early and very few new locations were introduced, which meant that the existing locations ended up with connections that make no sense for how far they are from each other. Like how I complained in my review of the Exalted corebook that the Linowan have an ocean presence despite being a thousand miles from the sea, or the way that the Realm has a base in Greyfalls even though it's a year round-trip.
One of the problems is the way that there were rarely any locations placed in between the existing ones in order to actually demonstrate the distances involved, and Masters of Jade fixes that pretty handily. Zebremani; the tomb-cities of Dazra of Irivande, ruled by the nemessary ghosts of their former inhabitants possessing their former bodies; the Empire of the Three Devil Princes, ruled by mysterious shapeshifters; Coindelving, the silver foundry-mill in the frozen North; the behemoth-island Grand Amanuta; the Thaumatarchy of Tessen-O; the Scorpion Empire... Reading those names gives me the same feeling as when I was reading the Exalted 1e corebook with its descriptions of mysterious cities, crumbling empires, teeming wilderness, and desolate wasteland, and even though that's not really what the book was about it's probably my favorite part of it.
What Masters of Jade is actually about is the Guild, the largest trading organization in Creation and one famous for being primarily mortal-run in a world where the supernatural is an ongoing and constant concern. I admit, I've never particularly liked the Guild for the same reason that I don't like the countries with implausibly large territories or trading relationships across hundreds of miles of trackless wasteland--it makes the world feel smaller when there's a single organization that runs nearly all international trade. The book actually does a lot to help rehabilitate the Guild in my eyes by making the case the the Guild's size is essential to its function. Individual Guild factors can be subverted and their interests taken over, but that's just one small area, and if the new owner still makes a profit it doesn't really matter. What really worries the Guild is the prospect of large-scale subversion, and their size and cell structure makes taking over the entirety of the organization a Herculean undertaking.
But not impossible, now that the Solars have returned.
Where Manacle And Coin was more of a lower-level view of a day-to-day Guild business, Masters of Jade deals mostly with the high level and the actions of the Guild as a whole. There's a section about how the Guild's power base is built on slavery, both because manpower is one of the few things in great supply in the Age of Sorrows and because slaves provide the only things of value that the Guild can trade with the fair folk, the powers of Hell, or the dead. Though the Guild is very careful on the last of those, because they actually have competition there--the Timeless Order of Manacle and Coin, the Guild of the Underworld. Or, taking account their respective pedigrees, it'd be more accurate to say that the Guild is the Timeless Order of Creation.
I really like the Timeless Order section, because it deals with the reality of the Underworld. Those with unfinished business become ghosts when they die, and Guild merchants are probably especially likely to become ghosts due to their obvious greed, without which they would not be successful Guild merchants. But the Guild's wealth is built on slavery and drugs, and they work thousands or tens of thousands in the fields to death every year to keep their markets supplied. Any member of the Guild who becomes a ghost is likely to face quite a few extremely angry ghosts with knives when they arrive in the Underworld--and this also serves the Guild's purposes, because it motivates its merchants to become extremely rich so they can finance lavish funerals and arrive in the Underworld with enough resources to obtain membership in the Timeless Order or other protection. Every Guild member lives in mortal terror of dying a pauper.
There's also an explanation for how the Guild manages to compete against supernatural threats, and it also comes down to its size. Against spirits, it relies on blackmail: agree to our policies and receive rich sacrifices, work against us and be starved of worship. Against Exalts, it relies on information: Exalts still have human concerns, after all, and if the Guild can find out what they want and put the Exalt in their debt, is if far better to have the Princes of the Earth work with you out of their own free will than to try to buy them. And if both of those fail, well, most Exalts have mortals they care about, and if the Guild can find that out as well, there's always the knife in the dark.
The book ends with a system called the Creation-Ruling Mandate, which sounds worse but plays better than the Mandate of Heaven from the Exalted Storytellers Companion. The Mandate of Heaven isn't necessarily flawed, but it's overcomplicated for all but the most focused nation-building games and has a ton of actions with names like Tiger Confounds Bear Legislation that are impossible to remember without memorizing them all. The Creation-Ruling Mandate abstracts out most of the attributes and changes the action names to simple ones like "Destroy Asset," which are less flavorful but much easier to use in play. The main drawback is that there are no example organizations provided and no example of play, so it's a bit difficult to figure out how the actions interact.
I remember liking Manacle and Coin and I wasn't sure how I would feel about Masters of Jade, but it managed to win me over. As someone who tuned out of Exalted 2e relatively early in the line, I wish there had been more books like this early on. They might have maintained my interest.
[4 of 5 Stars!]