The Divergence is the most common name for the creation of the Divine Gate, a barrier that prevented the gods from returning to the Material Plane and thereby diminished their influence on Exandria. It marks the end of the Age of Arcanum.
Many of the devout call it the Penance, and scholars of the arcane call it the Second Spark.
The end of the Calamity
The proximate cause of the Calamity, a war that killed two-thirds of Exandria's population and left permanent scars on its continents, had been the release of the Betrayer Gods from their extraplanar prisons. When the Prime Deities and their allies finally defeated the Betrayer Gods, they hoped to seal them away for good.
Following the Betrayer Gods' defeat, Melora, the Wild Mother, went to the most desolate land, the Barbed Fields where the cataclysmic final battles of the war had occurred, and planted the seed of the Arbor Exemplar as a symbol of rebirth.
The Divine Gate
To prevent a recurrence of Armageddon, the Prime Deities dragged the Betrayer Gods and their fiendish spawn from the Material Plane. Behind themselves and their defeated brethren, they erected in the Astral Sea a barrier known as the Divine Gate, which would prevent any god, including themselves, from physically crossing over into mortal realms.
This was not a unanimous decision; some Prime Deities didn't think creating the Divine Gate was truly in their best interests. But those deities were outvoted.
What was left behind
Not all creatures of great power were destroyed or banished before the construction of the Divine Gate. Some servants of the gods remained on Exandria. Some remained faithful to the gods they had served, while others developed their own interests. The great leviathan Uk'otoa, who had been a servant of Zehir until he was abandoned, was one of the latter. The twilight phoenix Desirat, mount of Asmodeus, had been trapped by the original Cerberus Assembly beneath Mount Mentiri. Udaaks were left behind in Xhorhas and lost their connection to the Abyss. Quajath, who had served as a scout for Torog, was presumed dead, but a fragment survived, trapped beneath Eiselcross. The solar Xalicas, who had served Corellon, was left profoundly disabled for more than a hundred years in the Greying Wildlands. Some immortal creatures remained deliberately trapped in prisons with the hope that they would remain there forever, including the Laughing Hand and Jourrael.
Of the greatest magic items bestowed by gods on their champions or crafted by the most powerful mages for the prosecution of the war, most were buried and lost in the devastation, others were locked away out of fear, and some were passed down from generation to generation. These items came to be known as Vestiges of Divergence.
Diminished divine influence
Many tieflings, who had been persecuted due to others suspecting them of ongoing association with demons and Betrayer Gods, felt relief after the Divergence seemingly locked those beings safely away.
The gods can still project power onto the Material Plane by whispering and making promises to mortals, bestowing knowledge and some measure of divine magic to their followers, or sending minions who can pass through the lattice of the Divine Gate, but their influence is paltry compared to what it was before the creation of the Divine Gate. Following the banishment of Lolth, her followers could feel the waning of her influence, which created an opening for some of her drow to stray to worship of the Luxon. Many mortal mages grew complacent about the Betrayer Gods' limits beyond the Gate until the Battle of the Umbra Hills, when fiends and even a Demon Prince tore their way back into Exandria in support of supernaturally twisted armies.
- See Critical Role: Tal'Dorei Campaign Setting, p. 7.
- See Explorer's Guide to Wildemount, p. 13.
- See "Chases and Trees" (2x65) at 2:41:47.
- See "The Fate-Touched" (1x103) from 3:19:40 through 3:20:51.
- See "What Is The Calamity" at 1:56 on the Dungeons & Dragons YouTube channel.
- See "Dubious Pursuits" (2x40) at 2:22:23.
- See Explorer's Guide to Wildemount, p. 17. See also p. 33.
- See Explorer's Guide to Wildemount, p. 31.
- See Explorer's Guide to Wildemount, p. 301.
- See Explorer's Guide to Wildemount, p. 32.
- See Explorer's Guide to Wildemount, p. 33.
- See their respective pages.
- See Critical Role: Tal'Dorei Campaign Setting, p. 110.
- See Explorer's Guide to Wildemount, p. 270.
- See Critical Role: Tal'Dorei Campaign Setting, p. 28.
- See Critical Role: Tal'Dorei Campaign Setting, p. 107.
- See Explorer's Guide to Wildemount, p. 20. See also p. 30.
- See Explorer's Guide to Wildemount, p. 46.
- See Critical Role: Tal'Dorei Campaign Setting, p. 29.