One of my favorite new game mechanics was the idea of plot stress, introduced in Cubicle 7’s FATE products, Legends of Anglerre and Starblazer. In essence, it creates a structured framework for how a plot/event/campaign will play out—a reactive ticking bomb, in a way, that progresses towards your plot’s end-goal. It consists of “plot stress” (health) boxes, usually 2-3 boxes on each of four stress levels. These are are ticked away when things occur in the game to complicate or progress the expected situation—these will often come off a predetermined list you’ve cooked up, but can really be anything that impacts the plot. When each stress level is filled up, the campaign takes a “Consequence” and alters the situation by progressing down your pre-determined plot avenue.
Let’s have a concrete example that’s not so freaking abstract, and less complicated by FATE terminology.
My current ICONS game—villains forced to run black ops for the SHIELD knockoff, ala Suicide Squad—got a weird multidimensional theme because half the players were connected to the infernal realm for one reason or another. One was a demon sent to Earth Superman-style, raised ignorant of his heritage and prophesied Dark Scion destiny; one player was a wealthy Golden Age bank robber whose family cavorted with demon-binding to extend their lifespan, and another was playing his demon-power-infused manservant. My original inspiration was a little Savage Worlds setting called Necessary Evil, wherein the players are villains in a world under alien attack, forced to fight off the alien invasion because said aliens captured all the world’s superheroes right before the campaign starts.
I liked the idea of a demonic incursion better than a squid-headed purple alien attack, so I switched that; really, the invasion and playing villains are the only things I remember from Necessary Evil, so that’s all I stole from that. The demons are an extra-dimensional race with lots of political infighting (kind of like drow, now that I think about it), with one or two houses after the Dark Scion character to save him, while the rest want to kill him—sealing the fate of the world by denying the prophisized events to come about, which will eventually cause the end of the world. Since the other two were tied to a different demonic house, the politicking and complexity worked out nicely.
Plot Stress Consequence Description   Minor Various factions put hit squads near PC bases   Major Cosmic events distract superheroes    Severe Demonic rifts open; search for Dark Scion    Extreme Destruction of Earth looms overhead
Dealing “plot stress damage” is based on in-play events. Say, killing a group of demonic assassins might do +1 to it; traveling to another dimension or making themselves known might do +2; revealing critical information did +1 (and there was plenty of that, thanks to one player accidentally creating an observation imp and forgetting about it); tagging something related to demons or the infernal realm might do +2. As things turned out, I’m re-structuring the stress track since the demonic invasion was triggered way early by inter-party politics, paranoia, and the mentalist trying to mindjack the avatar of Chronos, Liege of Time and Master of Your Future, heading into the far past to capture the Dark Scion for himself. (Yes, the Greek titan, plus some Galactus, if Galactus was a 29th-Century being of pure force and limitless energy. Rolling a 15—a Massive Cosmic Success—followed by two 10s and an 8 meant that the player almost, but not quite, succeeded.)
Another example, from my increasingly modified Pathfinder Serpent’s Skull game. I’d re-skinned large chunks; the first module’s boss monster Yarzoth (cleric of an evil Kull-style serpentfolk race; I was playing up their alchemical and magi-tech abilities) escaped and became an ongoing threat, and the serpentfolk threat increased, as was my end-cap goal of level 20 for the campaign. The stress track kicks in when the players arrive at an ancient ruined city (think El Dorado done in full sandbox mode) in the third module, tied to the rise and fall of the serpentfolk’s dead god.
This kind of tracking method is incredibly helpful when you’re dealing with a sandbox scenario with tons of triggered and plot-related events, let me tell you.
Plot Stress Description   Players tracked, ambushed by serpentfolk   Assassination attempts on player allies    Serpentfolk unleash alchemical monsters    The Dead God Rises! Ritual begins
Plot stress was built more around the setting and plot than the previous example. Exploring the city district where the serpentfolk lived dealt +1, and cleansing it of serpentfolk life did +2. Finding an avenue into the subterranean realm dealt +1; the El Dorado city was the bulk of module three, and triggering the key events to the next two modules (linked to it in plot and theme) also dealt plot stress. There were also a few other things—and my plot stress track did away with consequences, and expanded thing out by a bit, since my plan had been to take the plot past what was written.
The idea of plot stress pretty abstract—it follows movie logic in that some things happen at just the right time because it’d complicate things or look cool, because of the Raymond Chandler rule (when things get boring, men with guns enter the room), or because plot-wise everything would have led up to it by then. It’s a metric for the GM to determine when the game moves forward and track large-scale plot occurrences; it takes the “eyballing-it” method I already do and gives it a nice framework to build around. Most of the plot stress triggers were built in advance, though they anything else that was relevant would add to it. (Finding a way to kill Yarzoth might have started the track with three boxes checked, for example, and making an alliance between any of the serpentfolks’ traditional rivals would add +1 to +3 depending on who was contacted.)
In general, I don’t plan my games out ahead of time like most normal people. Instead, I tend to come up with a more checkpoint-oriented design: here are a bunch of key plot events, situations, or cool shit I want to include that will lead to each other, and successively, to some sort of end goal. How or when they happen is more up to actual play and the events within the game than anything else. Hence my love of plot stress; it codifies my Handwavium method with something less hand-wavey and more frameworked, yet still vague and flexible.