In real-world myths, legends, and literature, venturing onto other planes of existence isn’t simply a matter of visiting an unusual environment inhabited by strange creatures; it’s a journey with meaning expressed through layers of symbol and metaphor. Adventuring on the planes of the D&D cosmology is an opportunity to craft similarly meaningful and profound journeys.
Planar adventures ought to be extraordinary. As adventurers reach the medium to high levels of your campaign, they find more cause to venture beyond the confines of the world they call home and explore the planes. If you are ready for the party to undertake a truly mythic quest, such as to find a lost Artifact or an elusive extraplanar entity, the vast multiverse is yours to explore. As their physical and magical abilities are put to the test, the characters might find their emotions, values, and spirits challenged as well.
Throughout history, the teeming demon hordes of the Abyss and the regimented legions of devils from the Nine Hells have battled for supremacy in the cosmos. On worlds of the Material Plane, those who know of the conflict refer to it as the Blood War—a conflict that has raged for millennia, ravaging the Lower Planes.
The battlefields of the Blood War are concentrated in the Nine Hells and the Abyss, though fighting also takes place on the Material Plane, on the planes between those realms on the Great Wheel, and anywhere else demons and devils congregate. Although the intensity of the conflict waxes and wanes, and the front lines of the war can shift drastically, a moment never goes by when demons and devils aren’t battling each other somewhere in the multiverse.
Many demons and devils are obsessed with finding some advantage for their side in the Blood War, and powerful mortal adventurers are sometimes drawn into tangled schemes to that end. Additionally, open conflict between Fiends is a constant threat on most of the Lower Planes, even when it is incidental to the missions that bring characters to those planes. A simple quest to find a treasure lost in Hades becomes much less simple when the treasure is located in the midst of a raging battle!
Natives of the Upper Planes also have roles to play in the Blood War. While most of them are content to watch evil feed on itself, they still take steps to minimize the threat to the rest of the multiverse. Whenever the Blood War spills into a location outside the Abyss and the Nine Hells, angels and other emissaries of the gods—including mortals of exceptional valor—stand ready to intervene.
A portal to the Beastlands opens amid the branches of the World Tree.
You can use the Planar Adventure Situations table instead of the tables in the “Adventure Situations by Level” section in chapter 4 to inspire adventures that draw characters into the planes of existence. These adventure ideas are most appropriate for characters of level 11+.
| 1d10 | Situation |
|---|---|
| 1 | When magic fails to revive a dead person, the only solution is to venture to the Outer Planes to find the person’s spirit and either release it from some prison or convince the person to return to life. |
| 2 | People who venture into the woods keep accidentally wandering into the Feywild or the Shadowfell. They might never return, return with no sense of how much time has passed, or return dramatically changed. |
| 3 | A long-dead oracle is the only one who knows how a terrible prophecy might be averted, but the cataclysmic fulfillment of the prophecy has already begun. |
| 4 | A god has stopped answering prayers and won’t respond to any Commune spell. |
| 5 | A devil has tricked an angel into meddling in the Blood War, and the angel seeks mortal aid. |
| 6 | A ancestor of one of the characters must be convinced to bless the character before the full power of the character’s bloodline can be unleashed. |
| 7 | A foolhardy knight carried a holy weapon on a doomed mission into the Nine Hells, and the powers of Mount Celestia want the weapon and the knight’s remains retrieved. |
| 8 | A titan is imprisoned on an Outer Plane. The characters might be trying to stop those who seek to release it, or they might want to release it to help defend the world from a greater threat. |
| 9 | To prove themselves worthy of an even greater quest, the characters are sent to slay a horrible monster, win the favor of a powerful planar being, negotiate peace between two warring planar factions, or retrieve a long-lost item on another plane. |
| 10 | An item of legend is being sold at auction in Sigil, the City of Brass, or some other planar metropolis. |