One True Sequence

The good guys and the bad guys are both pursuing a set of MacGuffins or Plot Coupons that are hidden or distributed in what appears to be a random manner. In order for either side to achieve their aims, it is necessary that they get to these objects before the other side does. However, the objects are difficult to locate or reveal—research must be done, or inspiration must strike, before one of the hidden objects can be found.

Strangely, regardless of the differences between their resources and their methods, the good guys and the bad guys always find the same object at the same time and have to fight over it. There's never a case where the heroes get one while the villains head off in a completely different direction and get another, with no problems for either side. It's almost as if they're not random and have to be approached in a predetermined sequence that forces both sides into conflict. But that's ridiculous, isn't it?

A common trope in videogames, where, even though the bad guys seem to be everywhere at once, they'll always close in on a particular MacGuffin just as you do. A common video game variant is discovering the bad guys have had the final MacGuffin in their possession the whole time, forcing you to storm their stronghold and have a climactic battle against their leader. Another has the villains trading a convenient hostage for the items the heroes collected and then storming their castle. Yet another reveals that the villains were just letting the heroes collect the treasures so they could steal them later.

Examples of One True Sequence include:

Anime and Manga

In the Sakura Taisen TV series, five mystic stones, scattered and hidden through the capitol city, act as seals on an ancient and powerful demon. If even one remains, the demon cannot be released. Naturally, the bad guys are locating and destroying them, and the good guys can never find any but the next one the bad guys are about to attack.
Subversion: After the first 5 or so "Jewel Seeds" are individually fought over in Magical Girl Lyrical Nanoha, both the heroes and villains focus on getting the closest ones that the other isn't pursuing. The plot jumps ahead to after each side has collected all the ones available.
In Sailor Moon S, the Outer Senshi (good guys, although not initially in the same team as the main character) and the Death Busters (bad guys) are simultaneously searching for three talismans supposedly hidden inside unknown humans. In every episode, both sides arrive at the same time to examine the next Victim of the Week. It is hinted, however, that the good guys cannot extract the talismans themselves, and must thus rely on the bad guys to do the dirty work for them. (It's more than hinted in the anime - when they finally find where the Talismans are, the Senshi have to use the Death Busters' weapons to extract the Talismans.)
- Similar things happened with the Nijizuishou (Rainbow Crystals).
Exception: In the Yu Yu Hakusho movie "Bonds of Fire", there are multiple shrines that contain the energy needed to restore the flooded Spirit World. Rather than go to one after another, both sides split up and go to all of them simultaneously. This is probably because they didn't have time for a series of protracted battles, since it's a movie.
The hunt for Innocence in filler episodes in D.Gray-man's anime. Whenever they find a fragment of innocence, the Akuma have found it too and are after it. Cue epic battle! Often justified by showing that the bad guys were there first but were too inept to break through the barriers, solve the puzzle or resist the protective magic to the MacGuffin, and are just bashing away at those obstacles in the hope of getting through. Only the heroes have the resourcefulness to actually get through, so they always get it. Then the bad guys attack the heroes to try and get it, now that the barriers are gone.
Averted in Part II of Naruto: with the exception of Shukaku and the Nine-Tailed Fox (both of whom were/are sealed in major characters), the antagonistic Akatsuki has been able to collect most of the Tailed Beasts with almost no opposition from the protagonists whatsoever.

Film

Played unapologetically straight in nearly every Indiana Jones movie, where either the villains reach a MacGuffin first but can't attain it, allowing Jones to figure it out behind their backs; or with Jones arriving first with the villains chasing close behind, and then waiting at the dungeon entrance to steal the prize.

Live Action TV

In every single episode of Relic Hunter, the bad guys would appear right behind the good guys just as they've discovered the relic of the week.
Taken advantage of in The Key to Time Story Arc of Doctor Who, in which the White Guardian sends the Doctor to gather the six segments of the eponymous cosmic MacGuffin before they fall into the hands of the evil Black Guardian. It turns out that the Black Guardian's agent had been waiting by the final segment all along, having decided to sit back and let the Doctor run all the risks of gathering the first five segments, then steal them off him when he came for the last segment.
Star Trek: The Next Generation, "The Chase": While chasing DNA fragments of an extinct race, the Enterprise runs into Klingons, Romulans, and Cardassians at pretty much every single stop.
Seen in nearly every episode of Power Rangers Operation Overdrive, in which the Rangers and four factions of enemies are participating in a giant treasure hunt for five mystical jewels, with each individual jewel having another half dozen minor artifacts pointing the way to it in a linear clue-based system... but none of the five groups ever search for different artifacts than each other. Ostensibly, this was because the 32 episode season would've been done in 6 or 7 if they'd all gone after one jewel each.
Prison Break season 2 is basically 22 episodes of this trope. Mahone tracked down Michael by reading the Cliffs Note version of the plot tattooed on the latter's body and despite the tattoos not being in any particular order, Mahone always managed to figure out each development at the exact time Michael was enacting it.

Video Games

Subverted in Mother 3 , where the the player encounters scouting parties at the first few MacGuffins, while the Enigmatic Minion captures its opposing number. Even then, every time the enemy successfully claims one, your party is close enough to the area to see it happen. Five of the seven MacGuffins in this instance can be approached in any order, although the game pushes you in a certain direction to do so.
Subversion: In Paper Mario: The Thousand-Year Door, Bowser often reaches the locations of the Crystal Stars one chapter behind the heroes.
- PM: TTYD also has a variation on the "Let the heroes collect the treasures and then steal from them" path, which also ties into the villains having one of the treasures all along. Once Mario has collected 6 of the 7 treasures (the seventh being in the possession of the Big Bad and all 7 being needed to open the title door), the Big Bad leaves one of his more powerful minions at his base with the last treasure, with the thought "If he manages to beat Mario, all the better to him. When Mario beats him, Mario will just open the door for me".
Averted in some instances in Drakengard. While trying to defend the Desert Seal, if you have Arioch, she tells you at a certain point that the Island Seal has already fallen. Similarly, if you have Leonard and are trying to defend the Forest Seal, he tells you the Desert Seal is already gone.
Skies of Arcadia averts this for the Purple and Yellow Moon Crystals, when the bad guys are not involved at all, but plays it straight for the others. Belleza tags along with Vyse's team to have them recover the Red one for her; the natives who had the Green Crystal all along used it to fight The Empire, but only after the heroes arrive to see it; and The Empire only attacked Yafutoma for the Blue after Vyse finds it. Even the Silver Crystal ended up being straight with the Big Bad attacking right when the heroes were confronting the Omniscient Council of Vagueness.
Averted in Neverwinter Nights: Hordes of the Underdark in Shaori's Fell, where Sabal goes after the mirror pieces in a specific order, and even if you try to go ahead of her she ends up with at least one.
Averted and subverted with Final Fantasy IV's crystals.
- Of the light crystals, one is stolen by the main character just prior to the opening sequence, one is stolen just as the player arrives (too late for conflict), one is stolen when the bad guys actually win the battle, and one is explicitly retrieved by the player as ransom for a hostage.
- Then it's revealed that there's a second set of crystals. The bad guys have already collected two of the four dark crystals before the heroes even know they exist, and steal the other two after the good guys acquire them.
- Fortunately, the second second set (of eight lunar crystals) is content to sit tight and cheer you on while you tackle The Very Definitely Final Dungeon. Meanwhile, they carry on the task of keeping the Big Bad confined to the moon's core.
Mario & Luigi: Bowser's Inside Story doesn't subvert this, but contains enough Dramatic Irony to make Bowser think it did. From his perspective, the Mario brothers found the first Star Cure while he was dealing with a Boo researcher and his tower, and he beat them to the second Cure by a mile. In truth, the Brothers needed the researcher's invention to get the first Cure from a character he swallowed much earlier, and they helped him get the second one.
Played with in Fallout 2 when you reach Vault 13 to find The Enclave had already shown up and cleared out the population and a G.E.C.K. However, they overlooked one G.E.C.K. which you can take to your tribe...
Justified in "Nostalgia", since the Cabal can't take the tablets without Fiona.

Western Animation

Done in the first G.I. Joe Five Episode Pilot: "A Real American Hero", where the Joes and Cobra were after the rare elements needed to power the Mass Device.
- Averted in "Revenge of Cobra", where the objective was the three components to the Weather Dominator. Both teams sent out three teams to recover them simultaneously.
Xiaolin Showdown plays this ridiculously straight—every time a new Shen Gong Wu becomes active, the good guys and the bad guys will reach it simultaneously and even touch it at the same time, forcing an epic battle. Every. Single. Time.
- The show justifies it with the nature of the MacGuffins; they reveal themselves individually, showing up on both teams' scanners simultaneously, and both race to the location as fast as possible. They end up expecting the trope pretty quickly.
  - Possibly averted (albeit off-screen) when some Wu show up without us seeing their collection as well Wu changing hands between episodes on occasion. We only see the more dramatic Wu fights.
  - Definitely averted in the "Sands Of Time" episode. Jack brings his future self back from the future, and his future self knows the exact location of every Shen Gong Wu, so the bad guys have a serious advantage for a while.
Like Xiaolin Showdown, Jackie Chan Adventures plays this straight. A pitched battle is fought over nearly every talisman, animal, gateway and demon mask.