This article is part of a series for both the April 2020 RPG Blog Carnival and the 2020 Blogging A to Z Challenge.

We know almost nothing about Vryn, except maybe that is a spherical world, with many continents and islands surrounded by seas and oceans. Its landscape is littered with lines of gigantic inhabited mage-rings: conduits of mana which are controlled by ring mages. The age and origin of these mage-rings are unknown, and many are in disrepair. Enormous mana collection stations channel the energy of the leylines into the ring network, where all the energy of an entire continent is gathered in the Core States, sitting in the middle of the ring network, for use by the mage elite from the Ampryn League. Power over the Core States and the mana stream is contested by the Trovian Separatists, and arbiters work to keep the conflict from escalating into causing destruction for Vryn’s infrastructure.

Oh, yes: I almost forgot. Jace Beleren was born at Silmot’s Crossing on the plane of Vryn.

«Try to pretend you understand what’s important.»

For your campaign

Technologies and arcane devices of forgotten civilization and unfettered power, the eldritch machines of Eberron are a source of adventure and intrigue for even the most jaded heroes. Eldritch machines are ultimately plot devices that can represent the culmination of a villain’s master plan.

If you look into the pulp genre Eberron is based upon, you can find the recurring theme of a mad scientist building some crazy doomsday machine that does something sci-fi-ish. Keeping that in mind, I have always tried to stick to a procedure first proposed somewhere in Reddit:

1. Choose a scientific principle that has the potential to cause massive catastrophic damage to the world.
2. Create an eldritch machine that can cause the event in step 1.
3. Determine who created it and why.
4. Every good eldritch machine needs something to work. Some McGuffin that can be used as a way to lure in the party.
5. Decide what group wants to use the machine and why.
6. Set the party against them.

New eldritch machine: Mana Ring

Let’s talk about time travel (step 1). The thing is this: Many of Eberron’s elements are related to the number thirteen, but usually in the formula of “there are 12 + 1 missing”. For example, there are 12 moons, but one vanished long ago. The Mana Ring (step 2) is how our misguided villain wants to accumulate arcane power straight from the land in order to be able to bring the 13th moon back… and with it, the long lost 13th month of the year. By living an extra month, he will be able to fulfill a very confusing text from the Draconic Prophecy (step 3) that will provide him with his destiny.

The real difficulty with the Mana Rings is that they could only be activated psionically, so he needed to find talents who develop mind powers since their childhood. Luring them posing as a benefactor to teach them about their abilities, the kids were never seen again (step 4). He was successful, but he forgot to make sure he could come back… flash forward to hundreds of years later. His facility is used by some people just the same as he looked for, but without any guide, they became a cult venerating their lost mentor. Now they want to activate the Mana Rings again, power the spell and bring him back from out of time (step 5). Guess what: they kidnap someone close to the heroes (step 6).

The idea comes from a very special spell I read once in Ptolus, the Monte Cook’s setting for 3rd edition. We can still use some details as the final ritual to bring back the «Lost One». The following text comes from the Month of Vallis spell:

• You must cast the spell on the last day of the year within a sealed chamber no larger than one hundred square feet (it can be per caster level). Only you and your familiar can be in the chamber during the casting or the spell does not function (the only exception to this is if multiple people all cast the spell within the same chamber).
• During the month—the spell’s thirty-day duration—you cannot leave the sealed chamber or interact with anyone outside it in any way. Trying to leave the chamber sends you into a coma until the month ends (this can be dangerous if it happens early in the month, as you won’t be able to eat or drink). You can use the time to rest, study, or research, craft magic items, or perform similar actions. However, all materials you need must be on hand when the spell is cast. When looking out a window from the sealed chamber, you see the normal surroundings, as well as regular night and day cycles, but no other living creatures of any kind. Time truly does pass for you, so you had better have a month’s food and water on hand, or you may starve to death.
• You can cast spells during the month of Vallis, but those whose effects extend outside the sealed chamber generally do not work. A discern location cast to locate another person does not function, for example (but general divinations like commune or legend lore do). At the end of the month, the spell ends and you reenter normal time on the first day of the year.
• It is a subtle but important distinction that this is not a purely artificial magical effect like time stop. This is a real month, but most people do not experience it. During the secret thirteenth month, time has not stopped flowing, but rather you are experiencing what most people do not. You age a month during Vallis, spell durations proceed normally, and so on.

What is the craziest and most flamboyant doomsday machine you’ve ever had as a DM or destroyed as a player?