Something which has been brought up a lot recently deals with canon and non-canon classes and races from later WOTC publications. We state with the first PHB which classes are canon and which are not--the guide being that divine classes are all out and the only arcane class is Wizard. This actually extends to further publications as well. Amethyst has always been a low-to-medium magic setting. There is powerful magic but it's rare. So there should only be one arcane character per group.

As for races, the same rule applies--no races other than our own...so let's go back to classes.

Let's look first at Player's Handbook 2:

Avenger: A divine class so no.

Barbarian: This is the tricky one. While there is nothing to really prevent someone from choosing barbarian, it's something you would never see in my personal Amethyst game...at least if my players were good guys. Many of the nations in Amethyst are too civilized to really have them. Still, I won't say they are non-canon. If anything, I would avoid making these human. Chaparrans, pagus, sure.

Bards: If these guys were charismatic leaders with the power to sway the masses with their words (like the way we altered them for Amethyst 3.5 or how Goodman presented them in their book last year), I wouldn't mind...but PHB2 makes them spellcasters...so they're out.

Druid: Druids were present in the 3.5 Amethyst and we have lifepaths which emulate some of their powers. This is another tough one. I would definitely see them with the condition that they are rarer than wizards and nearly always non-human (once again, chaparrans being the best suggestion).

Invoker: This is another divine class so they are out.

Shaman: Another primal class and like Barbarians, would be well suited to the wilder races (chaparrans, pagus). This is another rarity but not against canon.

Sorcerer: Nope.

Warden: This one's good but still another common sight with wilder races.

So in conclusion, we can see how this is going. Arcane and Divine classes are always out. Primal classes are optional on the condition the fluff matches. I recommend connecting them to wilder race in Amethyst like Pagus, Half Pagus, and Chaparrans and some humans. You would never see a primal class with Damaskans, Laudenians, or humans from a kingdom or free house.

Now to Players Handbook 3:

Here is a shock...I could see allowing Minotaur. It is a mythological creature based on real legends...so I could see allowing it in canon.

Now PHB3 introduces Psionic classes. It should be noted that psionics don't technically break canon, but we don't explain why. For now, let me say that they are not a common sight and would be the rarest class in the game.

Ardent: As stated, we would allow Ardent...though we cannot say why yet.

Battlemind: Same as above...

Monk: Despite being called psionics, Monks are good.

Psion: Kinda pushing it, this one. Just saying. I would avoid it and keep with the other three.

Runepriest: Divine...waaait. Not necessarily. If you homebrew a rule swapping divine runs for Pleroma...I could see allowing it. This would be really rare and I would only allow it if a player was really begging.

Seeker: Returning to the Primal conversation with PHB2, this can be included, though it would be rare and more accustomed to wilder races.

So PHB3 spices things up a bit. For one, we make an exception for Runepriest and give a provisional tolerance to the psionic classes on the condition they be allowed sparingly.

After all is said in done, of the 14 classes in between PHB2 and 3, ten are good to go, though some are more well suited than others. Personally, I would allow any primal classes if the player wanted to play chaparran. But beyond that, I would recommend my player group stick with the staples.

In a strange sense of irony, it should be noted that (with the exception of the necromancer), the classes in both Forgotten Heroes: Scythe and Shroud and Forgotten Heroes: Fang, Fist, and Song are all allowed. And it's not just because they are also published by Goodman.