The Spellplague was a magical disaster that struck Toril‘s Prime Material Plane on Tarsakh 29 of the Year of Blue Fire, 1385 DR when the goddess of magic Mystra was assassinated by the gods Cyric and Shar. Mystra’s death tore the Weave apart and unleashed the raw magic contained within it, manifesting in Toril as a storm of blue flames that grew and spread quickly across the world, also infecting portals and planar gates.
Thousands of spellcasters were either destroyed or went insane due to the collapse of the Weave after Mystra’s death. In Cormyr, a third of the War Wizards were either killed or driven mad. Those who survived lost their ability to use arcane magic. During the decade that followed, magic was unreliable; in some cases it had the opposite effect, had additional unintended effects, or affected others than the intended target. Many magic items lost their power, or began to function in different ways.
Almost every part of Faerûn was affected by the Spellplague; certain areas were eliminated entirely, while others were created anew. It was through the planar gates that the Spellplague traveled across time and space, and reached the world of Abeir. In that world, the Spellplague first appeared in the southwestern region of the continent of Laerakond, which was torn apart in a powerful earthquake, and a portion of that region swapped worlds with the continental equivalent region of Unther from Faerûn, with Unther, in turn, being transported to Abeir. The rest of Laerakond was sent to the Trackless Sea, were it subsumed the lands of Maztica. Maztica was transported to Abeir, and Laerakond, which became known as ‘Returned Abeir’, remained on Toril.
The effects of the Spellplague on Faerûn resulted in areas called “plaguelands.” In such places, the blue fires of the Spellplague had literally altered the terrain and left pockets of wild or dead magic. Some humanoid spellcasters or others who ventured too close to plaguelands were also physically altered, a state called “spellscarred.” Spellscarred mages have survivable magical deformities, and some even learn to use these powers in battle. Those who were not so fortunate are called “plaguechanged,” creatures mutated by the Spellplague into terrible abominations. The likelihood of becoming spellscarred or plaguechanged increases as one continues to use magic, or as one spends an increasing amount of time in a plagueland.
By 1395 DR, the majority of the effects of the Spellplague had come to an end and most arcane magic had returned to a semblance of normality, with a handful of major changes to the way spells were cast. By 1480 DR, the Spellplague ended with the event known as Mystra’s Return: the goddess was resurrected along with the Weave, and magic became what it was before the Spellplague (though some areas with lingering effects from it remained). In 1482 DR, Lord Ao began the Second Sundering, as a way to restore the worlds of Toril and Abeir after the ravages of the Spellplague.
