In Dungeons and Dragons, the role-playing game, there is always a special villain that has to stay alive to the very end of the campaign. His or her demise may be the ultimate goal of the entire game and, when achieved, may actually bring an end to that adventuring group as they all retire with super-high-level characters and powers to wipe out cities with a snap of the fingers. This is the ultimate villain, the big bad, the controller who has operated behind the scenes until the very last dungeon door, the very last encounter.
Deep in the bowels of the City of Towers, Sharn, is the lair of Calderus. She controls the doings of the undead in the entire city, in fact, in the entire southern half of the continent of Khorvaire. The players have never yet defeated her directly. She is the one who turned the Dark Lantern agent, Lucan Stellos, into a vampire, forcing the adventurers to track him down, capture him, and return him to his Dark Lantern masters. She is also the one who leaked false information to the Royal Eyes of Aundair, the rival spy agency of the Dark Lanterns, to make Turkoman the wizard believe the player characters are evil double agents, causing him to begin tracking their every movement and learning their every plan. Of course, my players don’t know about that yet, so please don’t tell them.
Big bad villains are very useful to the story-teller known as the Dungeon Master. They allow the DM to start events moving that make no logical sense until the players begin to figure out that there is someone manipulating events behind the scenes and they must find that BBV out and track them to their castle or lair.
But adventures are not satisfying when the players attempt to cut straight to final scene and murder the big bad to bring about victory. That kind of meta-gaming strategy has to have severe consequences. Often that means that the villain must be at such an astronomically high level of ability that the player characters will all be turned into hop-toads after the first round of combat. Interesting adventure, that. The group of enchanted hop-toads have to avoid becoming part of the sauce in Calderus’ hop-toad soup, avoid the all the animated cutlery in the vampire’s kitchen, and escape to find Turkoman and get turned back into humans, halflings, minotaurs, and elves so that they can fight again another day and learn from their mistake.
Of course, it doesn’t hurt a bit that the wizard was watching by magical means when the players stumbled upon the big bad villain. He helped in their rescue because he realized that somebody had told him something untrue about the adventurers, and they really were useful to him and his spy schemes after all.
So, the big bad villain is an important kind of recurring villain to be met and pursued and met again, always driving the game forward to bigger and bigger doings and greater and greater rewards.