Magic in Sacawisha is the standard, 2nd-edition version, except for the effect of the Song of Woe. That's a rather large except, mind you. The history of the Song is described here. The purpose of this page is to describe its effects on the practice of magic in Sacawisha.
Essentially, the People of Woe, in singing the Song, cast a magic spell. The purpose of the spell seems to have been a communal self-immolation—in other words, the People wanted to die together, in what may have been ecstasy. In dying, they turned themselves into magical energy, in the form of Song Zones (about which, more later).
There was also an incidental release of magic force to the rest of the world. The problem: this “incidental” release was on a scale never before imagined. It was continent-wide, and overwhelming.
This power disrupted most intelligent beings' brains to the point of immediate death. All demi-human and humanoid races were susceptible to this—the death rate varied between 70 percent (dwarves) and 95 percent (elves). Among the survivors, roughly half were driven insane.
Among other intelligent races, the death toll varied more widely. Dragons, for instance, highly attuned to magic, were very nearly wiped out—it was sixty years after the Song before a dragon sighting was reported. The brutish ettins, on the other hand, only saw 30 percent of their fellows die.
Among animals, death was more rare. The most common effect was insanity. This created problems of its own. Animals (and people) who were driven insane by the Song became ravening maniacs, with an unstoppable hunger to kill, rend, and eat (not always in that order). These unfortunates were (and are) called the Mindlost, and they made life difficult, to say the least, for the survivors.
The final disaster the Song created was the virtual destruction of magic. With that much power reverberating through the “web” of magic around the continent, anyone (priest or mage) trying to tap magical energy stood a good chance of losing his or her mind. The more powerful the spell, the higher the risk was of insanity. This effect took fifty years to fade away. By that time, the use and study of magic had severely declined. Eighth and ninth level spells have been completely lost (and are not available to PCs unless they dig them up in abandoned cities or the like).
The lasting effect of the Song was the creation of Song Zones. These were created when the People of Woe were turned into magical energy. One of the People would create a small, weak zone with a fairly short life span; a group, concentrated in one place, would make something a bit trickier to deal with.
There are three types of Song Zones:
“Outer” Song Zones can be destroyed. This takes at least two mages of 8th level. One stands within the zone, one outside. Then, they both cast dispel magic (where the zone is a dead magic zone, the inner mage must cast his dispel exactly 75 seconds after the mage outside the zone). This will work on zones up to 125,000 cubic feet in area (50' X 50' X 50'). For every 125,000 cubic feet beyond that, two more mages of at least 7th level are required. No one has yet figured out how to disrupt an “inner” zone.
Song Zones fade, slowly, over time. For every ten years, a zone will lose about one million cubic feet of area (that is, 100' X 100' X 100'). Since the Song of Woe, this has reduced the size of an average Song Zone by an area 650 feet on a side.
Finally, Song Zones migrate (they're not coconuts, you know!). They move very slowly: no more than 100 feet per year; most, less than that. They move in three dimensions; some are sinking into the earth, others are rising into the air. No mage has determined why zones move, or why each zone moves differently.