In preparation for my conversation with Levi Combs about Planescape and the subject of extraplanar adventures as a whole, I started thinking about what the general appeal of plane hopping might be. I've alluded to it in my home games, but I've never included it as a possibility for characters. For many people, planar travel falls squarely into the territory of “immersion-breaking.” After all, your Roman-themed RPG world would be completely shattered if a flying saucer were discovered in the wreckage of Pompeii that transported your Legion to a pulp sci-fi alien planet, right? Well, no. That’s wrong actually. I used to think that way myself, but I have since come to a realization that anomalous instances of things alien to your world don’t break the setting. In fact, inexplicable occurrences in a campaign setting are usually called “Adventure Hooks.” The problem with plane-hopping adventures for me is that they’re often treated like Rick and Morty instead of The Wizard of Oz or The Odyssey. The fact of the matter is that being transported to a plane foreign to the one you hail from is a nightmare scenario whether you realize it or not. It should usually happen by accident and, in the rare case that it’s sought out by adventurers, the unforeseen consequences of making that decision should be massive. Once you enter another plane, it should be a long, strange trip home.
In almost every Appendix N story that features planar travel, it happens by accident. The best examples of this are Edgar Rice Burroughs’ Barsoom series and Poul Anderson’s Three Hearts and Three Lions. In both, the protagonist finds his way into a strange new world under duress and by accident. In fact, this is something that these stories have in common with The Chronicles of Narnia, Alice in Wonderland and The Wizard of Oz. The reason behind this is that often the protagonists are at the end of their ropes and need to learn some kind of lesson within the strange environs of the world they find themselves in. Moving this into the realm of the table-top, the best way to get your players to travel into another realm is to put them in a desperate situation. If the players are running from a monster and hide themselves in the first cave they find, maybe roll a percentile die to determine how likely they are to find a portal to a new dimension. Maybe it happens because someone messes with the wrong artifact in a dungeon. Maybe a teleportation spell goes wrong. There are a number of ways for players to stumble backwards into extraplanar adventures and using them will go a long way toward creating that feeling of going down the rabbit hole.
Once your players are in the new plane, resolving the issue at hand should be far from a cake walk. After all, not only are your players unused to the environment, but the environment will be unused to your players. To the natives of that plane, your party will be an oddity at best and a perceived alien threat at worst. This could happen immediately or it could happen after the players stumble into spots of trouble out of sheer ignorance. Too often GMs portray dimensions as like Earth but everyone has a beard instead of some place truly alien. It’s worth the extra effort to really hammer home that your players aren’t in Kansas anymore. This is the challenge presented by dimensional travel. They may get stuck with the Lotus Eaters or imprisoned by a witch or on trial for vague crimes where the verdict will most assuredly be to their detriment. It will be a little, or a lot, unfair and the players will be pushed to their limits to solve the crisis at hand.
On the other side of the coin, the rewards for rising to the challenge of a foreign plane should be generous. Bill and Ted enter the Phone Booth right before their rock concert at the end of Bogus Journey and then come back as leveled up rockstars to perform. It’s that moment of stepping through the portal with a sick fade haircut, a full beard and an assload of alien weapons to stomp the menace you left behind on your home plane. You’re gonna slaughter every single suitor to your estranged wife and set your house in order. Nappa and Vegeta will be horrified at what the Scouter says your power level is now. I’ve said it over and over, but risk-reward is the beating heart of role-playing. Going to another plane is super high-risk, so surviving should come with some pretty hefty rewards.
Exploration of other planes is one of the most frightening things that players can encounter when done correctly. The chess pieces have been overturned and you’ve been dealt a hand of cards for an unnamed game. You may try to play it like poker, but it turns out to be euchre. It’s a hardscrabble fight against an alternate reality. It’s an existential nightmare. It’s also just another day in the life of an RPG character. Embrace the chaos as you put your players through their own personal Odyssey.