The world of Dungeons & Dragons can be just about anything you want it to be; you are free to create whatever you want for you and your players. The lore and universe that is published in the core books are detailed, sprawling, and fascinating. The expansion books that periodically come out only add to this wonderful world. Many of the planes in the multiverse come with an additional effect to levy on the party, which is optional and this adds to the excitement. So, if you're not quite satisfied with having an adventuring party march through the standard medieval fantasy world we all associate with Dungeons and Dragons (known as the Prime Material Plane in the multiverse), here are ten other planes of existence that are sure to mix things up.
9 Mechanus
The plane of Mechanus is described as what is essentially the inside of a giant clockwork device. The ground is made of huge horizontal gears that churn and grind, and mountains are towers of mechanisms that stretch skyward. It is inhabited little creatures known as Modrons and their creator Primus. Primus’ main goal is to bring perfect order to the multiverse and the Modrons act as a hive mind to carry this. The Modrons have a strict hierarchy that is forever maintained in a careful cycle. The side effect of being here entails that all damage dealt there is an average of what it could be. Players could have an interesting time with combat as well as interacting with the Modrons.
8 Hades
Not to be confused with the Greek god, the Plane of Hades is a place of despair and bleak landscapes. It has three layers known as the Three Glooms that are inhabited by souls not bound to the planes of good or evil. Here, an awful metamorphosis occurs on the poor specters.
They transform into horrible fat larva, keeping their faces frozen in suffering and vague memories of the life they once led. This effect can be applied to an adventuring party. While the sturdy souls of player characters can resist for a while, if they linger too long, they will eventually have all of their emotion and will be drained from them and turn into a larva like the other souls.
Limbo
Limbo would definitely make for an interesting setting for a campaign. Limbo is a place of utter and absolute chaos. Matter changes states at random intervals, there is no gravity, so islands of structure float aimless amid roiling storms, and if you can find the ability to concentrate amongst the madness, one can shape the plane to your will.
While being able to control matter and shape it the way you want is a great side effect of Limbo, a party has to beware of creatures known as Slaadi. They come in various colors that all do unique things ranging from implanting tadpoles in their victims to casting powerful magic.
7 Elysium
Some of these planes are quite chaotic and seem naturally like bad places to be. However, Elysium is different. It is a veritable paradise, a fantasy parallel to Heaven. While this might not seem like a place where grand adventure could be found, the optional effect for this plane could be an interesting plot point in a campaign.
The longer a creature stays on the plane of Elysium, the bigger the chance becomes that the creature won’t want to leave. Once the creature is totally enthralled by the plane, even if the rest of their party can haul them out, the creature will spend the rest of their days trying to return.
6 Plane of Water
As one of the four elementals planes, the Plane of Water is made purely of its titular element. It's a never-ending ocean that stretches forever and is infinitely deep. Here in these mystical waters, there are many different sceneries for an adventuring party to explore such as the palace of pearls, the deeper sea where giant monsters lurk, and even pirate battles on the choppy waves above.
Navigating this nearly land-less plane will be full of unique challenges and adventure. The party could discover the Isle of Dread (one of the only landmasses on the plane), whether supernatural storms or even be transformed into merfolk to explore the depths.
5 Plane of Earth
The Plane of Earth is yet another elemental plane that could be a premier setting for a campaign. The Plane of Earth is made of two main parts, the surface made of mountains with no peaks and canyons with no bottom, and a labyrinth of caves, caverns, and tunnels that burrows beneath it all. The surface is rather plain, being made up of craggy rocks and stone. Below is where the real adventure lies. Almost anything can be found in the underground; gems, riches, burrowing creatures, and grand societies. A party sent into the maze in order to find a certain treasure or mine a particular gem will have no shortage of encounters, maze navigating, and perhaps even mystery as they try and escape.
4 Feywild
The Feywild may sound like a mystical, fantasy name but in reality, it's quite self-explanatory. Fey is a classification of a creature in Dungeon and Dragons. They mostly equate to what we would consider to be fairies and sprites. While it is nowhere near as chaotic as Limbo, the Feywild is still far from a plane of order and reason. It is a plane of wilderness and jungles that are alive with creatures. Many denizens are ruled by the extremes of emotions that can make interacting with the locals difficult, if not dangerous. In addition, the first effects of the plane is that time passes differently in the Feywild and thus, sometimes travelers lose their memories after they return to the Prime Material Plane.
3 Ethereal Plane
At first glance, the Ethereal Plane might not seem that exciting of a place to host an adventure. Simply put, the Ethereal Plane is a sort of in-between that can reach and be reached from several places in the multiverse. Its shrouded in fog and anyone there is almost like a ghost, they cannot affect other planes and other planes cannot affect them; they can only observe.
The only way beings in the Ethereal Plane and its borders can affect others is through magical means. This could be a tense, thriller/puzzle setting as a party is trapped in the Ethereal Plane and must find ways to affect the Prime Material Plane in order to avert a world-ending catastrophe.
2 Astral Plane
The Astral Plane, much like the Ethereal Plane, is another place where planar travelers can have a hub to connect to other planes except on a grander scale. One can reach just about every plane of existence from here. There are also psychic winds that howl across the starry expanse that can shove you to parts unknown and drive you mad. Magical ships sail through captained by the mysterious and viscous Githyanki and countless other creatures pass through on their way, so there will be plenty of danger to combat. One can go to the Astral Plane physically or spiritually but if you go there in spirit, you run the risk of having your soul separated from your body, resulting in permanent death.
1 The Nine Hells of Baator
The Nine Hells is more than just a stop, it could encompass your entire campaign and story in a difficult and dangerous odyssey. The Nine Hells has nine differently named layers with Nessus at the very bottom. The Nine Hells is ruled by the powerful Asmodeus from Nessus and each other layer is ruled by an archdevil that answers only to him. There is a deep lore for each level and its archdevil rulers, including the fact that the legendary villainess Tiamat, Queen of Evil Dragons is imprisoned there. In addition to battling off hordes of devils, a party braving the Nine Hells also must fight the influence of the plane or be turned permanently evil.