It is always dangerous (and frequently difficult) when introducing a villain in dungeons and dragons, especially a big villain meant to last a while. If they’re near the players in power initially, there’s a good chance the players might just take them out immediately, bringing their villany to a premature end. If they’re too powerful, the players might take a shot at them and be wiped out by the response. Additionally, there’s the stretch in credibility that comes when a super-powered entity doesn’t just lay waste to the plucky young heroes at their first meetting. You can make a good story out of the villain taunting the weaker protagonists, egging them on for some dramatic final confrontation, but that requires a certain style of story and it is difficult to smoothly employ in a shared storytelling medium like a tabletop RPG.
So, when I decide I want to introduce one or more big bad villains in my game, the thing I spend the most time considering is why they’re exposed to the players and why they leave without taking them down. In one campaign, I wound up making them the head of a system that tests up and coming mages, so they could be around to watch and introduce themselves without giving them any personal stakes in the fight. In fact, they had a system of rules that prevented them from interferring since they were trying to determine if this lesser mage, the one the players actually fought, was worthy of joining their organization. Now that the introduction has been made, this figure can taunt from a distance, pick at the fraying edges of the party, and generally just appear as a distant villain. Especially because this party proved stronger than the fledgling member of this villain’s organization and they might want to employ the party in the future, to test other members and the systems they support.
In another game, a much fresher one with only a few sessions under its belt, I needed a way to hint at the larger plot the party will be dealing with, establish stakes, and introduce trouble to the world given that it was in a state of stable (and corrupt) liberalish democracy. While not ideal or utopian, it was an advanced world with solutions to most of the dangers and societal problems that drive the style of RPG my players wanted. This is a world we created together, so I wanted to respect that but still provide the players with goals to work towards. But how do you introduce some super-powered creatures to the players, making them aware of a growing problem in a way the rest of the world isn’t, without making it feel cheap?
The short answer is summoning rituals (which are risky to stick into combat, as recent experience has taught me. Only a natural 20 allowed the ritual to complete) and teleportation magic. If the villains need to be brought into the world and then wish to hide themselves away, you can have them show up for exactly one round of combat and then have them teleport away. Drop another awful creature into their lap to explain why the villains left without killing the players, throw in some weird illusion/time/space hijinks, and see how it plays out. There’s no guarentee that the players will feel this interaction was earned or natural, but if you can tailor it to your players and play off their expectations, you have a better chance of succeeding.
I am still waiting to see if the latter will play out the way I want (we had to stop mid-battle, right after the villains disappeared), but I’m interested to see how they all respond to it. If any of them are reading this, then it will expose what I’m trying to do, but not why. I can live with that. I feel like it’s probably obvious already, given that we talked about the ritual they failed to interrupt (the bad guys rolled high initiative, the players rolled low, and the biggest interruption to their casting was negated by a natural 20 on a concentration check, which meant the ritual was completely quickly), but you never really know.