IMO it’s more practical to treat the demise of the Shadow Weave as something with additional elements of story behind it.
To this end I view the creation of the Shadowfell as the result of Shar hoarding what power she could from the Weave before Mystra was destroyed.
This could be one explanation as to how Shar was able to fold the plane of Shadow into the Shadowfell while simultaneously keeping her own divine Realm from disintegrating as the structure of the outer planes collapsed. Forming a new plane while holding your own together would have been massively draining, even for a goddess of Shar’s power and might.
Yet in the current Realms she stands at the pinnacle of her power. Thus it’s likely she used the Shadow Weave to do what she did.
If we advance the idea further, we can posit that the trappings of the Shadow Weave still exist to some degree in the Shadowfell as reserves of raw magical power (think free floating pools of shadowy radiance) and so provide a source of power to those who know how to tap it.
True the Shadow Weave did go away around that time, but from a DMing perspective, it's not really necessary or even feasible to treat this as an absolute (like some sort of light switch that got turned off).
IMO it’s more practical to treat the demise of the Shadow Weave as something with additional elements of story behind it.
To this end I view the creation of the Shadowfell as the result of Shar hoarding what power she could from the Weave before Mystra was destroyed.
This could be one explanation as to how Shar was able to fold the plane of Shadow into the Shadowfell while simultaneously keeping her own divine Realm from disintegrating as the structure of the outer planes collapsed. Forming a new plane while holding your own together would have been massively draining, even for a goddess of Shar’s power and might.
Yet in the current Realms she stands at the pinnacle of her power. Thus it’s likely she used the Shadow Weave to do what she did.
If we advance the idea further, we can posit that the trappings of the Shadow Weave still exist to some degree in the Shadowfell as reserves of raw magical power (think free floating pools of shadowy radiance) and so provide a source of power to those who know how to tap it.
The FRCG book says that the Shadow Weave is gone now, so it's gone.
The FRCG book says that the Shadow Weave is gone now, so it's gone.
Feel free to take that attitude. I don't mind at all.
I learned a long time ago not to treat the sourcebooks literally or assume that just because something isn't written about that it can't be.
The fallout of Mystra's death which shattered both the Weave and Shadow Weave and created the Elemental Chaos likely also blended the Plane of Shadow and Plane of Negative Energy. This new plane became known as the Shadowfell (since fell can refer to an 'evil taint' to something, so it's a 'corruption' of the Plane of Shadow with the necrotic energy of the former Inner Plane).
The remnants of the Shadow Weave may have blended into the Shadowfell as well as the remnants of the Weave possibly blended into Faerie/Feywild. Both also left residue on Toril just as the elemental planes did as they merged into the Elemental Chaos. All these combined contributed to the Spellplague and the changes it wrought on Toril and why it settled over time as the energy seeped off to other planes and reality re-asserted stability over Toril.
Of course this is all just a suggestion but it fits with what's printed without contradicting anything we've seen in the novels or the rulebooks.
The Shadow Weave was/is the same thing, but relies upon the Shadow Power Source (which comes from the Shadowfel, which 'ate' the plane of Shadows, the Negative plane, and perhaps the Demi-plane of Dread as well).
In 4e, neither Weave exists anymore, so users are now forced to access the power-sources directly. The way I look at it, it means they have greater powewr with their understanding (multiple-castings), but can handle 'less' types of different magic (spells). In other words, 4e's magic requires much more work to obtain even one 'dicipline' (what were spells in 1e/2e/3e, and I think are just called 'powers' in 4e), but once learned, a person can draw upon an almost limitless supply of energy for that one power now. The reason why mages can't learn dozens of spells like they used to is that each dicipline is more exacting, so that less can be learned in the same amount of time (with those user-friendly Weaves gone). Eego, less spells, but more usages of the spells you do learn.
That means that power-source is exactly the same, but how your PC is interacting with is is diferent. That's just a flavor-aspect, though, and doesn't really need to be reflected by game-mechanics.
I learned a long time ago not to treat the sourcebooks literally or assume that just because something isn't written about that it can't be.
Which is one of the few things we've all (just about) learned to agree on. NOTHING is canon unless you insist it is (in YOUR games).
