A couple of years ago, then Pixar storyboard artist Emily Coats tweeted pieces of advice on making stories that she had picked up from working with Pixar, which were later compiled on in several places on the internet, such as this io9 post. Later, Dino Ignacio created image macros of the individual rules which I am using in these posts.
Rule #7: “Come up with your ending before you figure out your middle. Seriously. Endings are hard, get yours working up front.”
This one requires an important modification for tabletop RPG’s because as a Game Master, endings are most emphatically not yours to figure out. Endings are firmly in the players’ court; they are the ones who make the choices that determine how things play out, or else they might as well not even be there.
What is within your purview is the climax, the pivotal scene that gives the players the opportunity to decide the outcome. That is what you want to come up well ahead of time. If you know who is involved and what’s at stake in the climax, then you can make sure that the proper characters are introduced well ahead of time, and that any relevant MacGuffins have been established. You’ll have to modify things along the way, but it’s a lot easier to plan a satisfying trajectory if you have a point to aim for.
In one game I ran, I didn’t just figure out the climax ahead of time, I gave the players a sneak peek at it. Borrowing an idea from the WotC D&D forums (circa 3rd edition), I started the game by giving the players high level versions of their character sheets, but injured and with many of their resources expended. They then played out part of a climactic showdown with the campaign’s apparent villain until it became clear that they were losing and snapped back to their low-level characters. This gave them an immediate reason to seek out the other allies they had seen in the vision (bringing the party together), but it also gave them an idea of what was at stake. Then, midway through the campaign, right when they had defeated the villain that they thought would be the main villain for the entire campaign, I gave them another vision of the future, with a fight that featured a different villain but eerily similar circumstances, showing that their actions had had an impact on the future, but that it was not yet enough to save them.
An aside, because it doesn’t really fit with any of the other rules and I think it’s important (and this would otherwise be a short post): I strongly recommend introducing your villains early. The earlier you introduce your villain, the more opportunities you have to develop them as a character, the more opportunities you have to show in specific ways how they are affecting the world, and the more opportunities the players have to develop around their reactions to the villain. An illustrative set of examples is the Baldur’s Gate series of CRPG’s. The first game introduces its villain, Sarevok, to the player by having him show up and attack immediately after the prologue/tutorial and kill the PC’s father. Consequently, every part of the game’s main plot can be tracked and understood in the context of that character, lending him considerable development despite the fact that he spends most of the game operating through minions and intermediaries. Likewise, the second game opens up with the PC being tortured by its villain, Irenicus, who kidnaps one of your friends and haunts you in your dreams. Both of these villains are highly memorable and are still referenced to this day. Contrast with Throne of Bhaal, the expansion to the second game, which doesn’t reveal who the actual villain is until about the final hour. As a result, much of the game feels directionless, and the villain isn’t particularly engaging or memorable (even if you’ve played the game, you’ll probably have to google it to remember her name).
While I’m on the subject of CRPG’s and endings, it’s worth discussing one more thing: CRPG-style epilogues. I’m talking about the end-of-game denouement common in Bioware RPG’s or the Fallout series, where the outcomes of actions and events in various areas of the game are narrated to the player to show the consequences of their decisions in the aftermath of the game. It’s tempting to bring these into your tabletop games as an epilogue after the dust settles, but it isn’t really a good fit. CRPG Epilogues are a product of the expense of creating additional content for branching story paths–at some point they have to cut things off and basically freeze time in a zone such that nothing really changes for the rest of the game. As a GM, you are not under that kind of constraint, so you don’t need to wait until the end of the game to show the players the consequences of their actions; you can revisit them through messengers or rumors reaching the players and give them the chance to react and attempt to put things back on track (or repair some of the damage they may have inadvertently caused). Placing epilogues “after the action” risks denying the players agency, whether because you narrated their characters doing things they wouldn’t do, or because you’ve laid out events that they would have wanted to intervene in. If you really want to do an epilogue, take turns giving each of the players the reins to narrate out what their player does after defeating the Big Enemy, chiming in only as necessary.