Planeswalkers (or 'walkers) are among the most powerful beings in the multiverse.
Description
The defining trait of planeswalkers is the ability to travel between separate universes with ease, while the vast majority of people throughout the multiverse are not even aware that other worlds exist besides their own. Planeswalking is a form of magic. With enough time and mana, or with specialized spell knowledge, or with access to enormous power, it's possible for a planeswalker to transfer clothing, artifacts, and/or creatures with them as they planeswalk.
A planeswalker is specifically a being who possesses a planeswalker's spark, an imprint of aether on a being's soul. In a way, Planeswalkers function as avatars of the Blind Eternities. One in several million sentient beings is born with a planeswalker spark, and having it ignite is exceedingly rare. Some number of these die shortly after completing their first planeswalk. There are a rare few beings who, through various means, are able to travel between planes, but they are not considered planeswalkers.
There is only an incredibly remote chance that any given sentient and natural being is born with a planeswalker's spark. Planeswalkers can be born at random, with no outward signs of their latent power. Such a being is called an "ember". Fewer still will ignite their spark. When an ember is put through a period of extreme stress or strong emotion, the spark can trigger, causing the individual to ascend and become a planeswalker. Ignitions are often caused by near-death experiences, though it is possible for an ember to undergo such an experience — even dying — without igniting their spark.
Planeswalking
It can take weeks or months to get the hang of planeswalking, and it can take a lifetime to master it. The act of Planeswalking is a spell, and like how every mage practices magic differently, every planeswalker planeswalks slightly differently. Some can planeswalk swiftly, some more slowly. Some require great effort to planeswalk, some can do it with ease. Some can planeswalk again in a short amount of time, some can take a while. Some can carry more inorganic material with them. A rare few can planeswalk organic material.
Planeswalkers can planeswalk to specific locations, though their accuracy is determined by their experience, mana, time, and familiarity with the destination. A planeswalker can also effectively teleport by planeswalking to the Blind Eternities and then back to another location on the same plane.
Planeswalkers have described planeswalking differently depending on the individual. One planeswalker described planeswalking as "like walking on clouds in a rainstorm through a rainbow. The colors were vibrant yet misty — at the same time," while another noted that she only felt nausea. Another planeswalker likened it to floating it in water, and another described her sense of other planes and planeswalking as akin to her peripheral senses. A planeswalker's arrival can be sensed by the sound of their displacement of air.
Any planeswalker can follow another planeswalker by following the "aether trails" in their immediate wake. A planeswalker can potentially describe a plane or method of locating it to another planeswalker, but this method can be unpredictable.
It is unknown if a planeswalker's soul can planeswalk after death.
Requirements
For a creature to become a planeswalker under normal circumstances, they must have a soul and be a mage of some kind. Artificial creatures like Angels and Demons, which are manifestations of mana, do not have the right soul or essence to hold a spark, although very rare exceptions exist.
Though the spark is inherently magical, beings with no magical training can attain a spark.
Player Options
Players may choose to have their character start as or become a planeswalker, granting them the ability to travel to other worlds. Players can also choose to opt out, meaning their character will not be able to leave the world they are on if the adventure calls for it, meaning they simply would select or create a new character to play as on a new world. Players can choose to have their spark ignite as part of a story arc during the campaign, at the end of the campaign, or even start the campaign having just planeswalked to this world and now having to learn how to use their new abilities.
A spark igniting mid-campaign can be very exciting, as when a character planeswalks for the 1st time it is to a random plane. This howvever means your character has just left the current campaign, meaning you'd need a backup character until your original charcater learns to planeswalk back, which could take them weeks or months. Typically we have been following each character as they explore the new world they are on as a brand new adventure, while the rest of the players build new characters native to that new world, further expanding the roster of potential characters each player could choose from. If players choose to mkae their charcaters be potential planeswalkers, that gives them flexibility to take any of their characters to any world they want and mix and match different party compositions.
Mechanics
Since a spark is ignited by an extremely emotional experience and plaeyrs are in control of how their characters feel and react to things, it will be up to the player to decide if something that occurs is emotional enough to potentially ignite their spark. As rare as having a spark is, it's even more rare that they actually ignite, therfore simply reaching an emotional peak may not be enough to ignite the spark. Sometimes even dying doesn't ignite the spark. To represent such a rare occurence, it will require a d20 roll of nat 20 to ignite the spark. This may seem unreasonable, but it should be hard to achieve and if it's too easy to do it may become too disruptive to the campaign to have characters constantly abandon the party because their planeswalker spark ignited.
