The Spellplague, also called the Storm of Blue Flame, was a disaster that struck on Tarsakh 29 of the Year of Blue Fire, 1385 DR. It continued for a decade, leading to the Wailing Years, during which arcane magic ceased to function and the world was transformed. The effects of the Spellplague would be felt for a century.

It’s believed this calamity was caused by the death of Mystra, the goddess of Magic. For eons, magic had been bound within Mystra’s Weave, the universal structure of arcane forces, and her death tore the Weave apart and unleashed the raw magic contained within it, creating the cataclysm that was later known as the Spellplague.

The Spellplague manifested as a storm of blue flames that destroyed several lands, later called the Plaguelands. Almost every part of Faerûn was affected.

The ground rumbled and heaved up and down like the surface of the sea. Curtains of blue flame swept the landscape, reshaping the land by cutting crevasses or lifting and sculpting the plain into hills and ridges. Shards of earth wrenched themselves free and became earthmotes. Waves of azure fires appeared everywhere, killing whatever they touched.

Rifts opened in the Underdark beneath the sea, causing the level of water to drop, cutting many ports off from their livelihood and creating the Underchasm. The sudden shifting of continental bodies sent tsunamis all along the island and coastal regions of Faerûn, devastating them all. Islands and peninsulas were drowned, and vanished completely.

Thousands of spellcasters were either destroyed or went insane due to the collapse of the Weave after Mystra’s death.

In the wars between the gods, several gods were killed, driven into the nine hells, or lost in time and space.

In Waterdeep, the Walking Statues of Waterdeep appeared in the city and began to rampage.

Political upheaval across the lands resulted in many attempted coups, invasions, and uprisings. Nations that had relied heavily on arcane magic for defense or controlling their population collapsed under the anger of their subjects.

Finally, near the end of the 15th century, the Spellplague finally ended with Mystra’s Return. The Weave was resurrected with the goddess, and magic became what it was before the Spellplague, though some areas with lingering effects from it remain.