KesselZero
First Post
Class is the core of how your character fights and adventures, and themes and backgrounds are extra add-ons. Outside of the fluff (the "who/how/why" stuff) I think the distinction WotC seems to be drawing is that themes give you additional or altered combat abilities (via feats, generally) and backgrounds give you skill training. So the reason you wouldn't have an Alchemist Werewolf (at first level, at least) is that you'd be getting a set of powers from both (the ability to make alchemist's fire to throw at your enemies and the ability to shift into wolf form, gaining combat bonuses, for example) and thus would be more powerful than your pals. This is obviously a very gamist explanation but I believe it's what they intend, and it does give a clear division between the two.
Obviously this raises the question of what should be a theme and what a background, and I like the proposed answer that there can be different versions of the same idea (the Knight example above), some of which grant combat powers (themes) and some of which grant skills (backgrounds). So there could be an Alchemist background that gives you training in Arcana, Alchemy, and Herbalism or something, totally separate from the Alchemist theme that gives you combat-useful abilities.
I also look forward to the ability to add themes as you level, so your character can grow with the plot. So your Alchemist could get turned into a Werewolf at some point.
Obviously this raises the question of what should be a theme and what a background, and I like the proposed answer that there can be different versions of the same idea (the Knight example above), some of which grant combat powers (themes) and some of which grant skills (backgrounds). So there could be an Alchemist background that gives you training in Arcana, Alchemy, and Herbalism or something, totally separate from the Alchemist theme that gives you combat-useful abilities.
I also look forward to the ability to add themes as you level, so your character can grow with the plot. So your Alchemist could get turned into a Werewolf at some point.