Everyone Has a Power Ring

""Every game it's another buncha legendaries! How ledgedary are they if'n everyone is?""

- VG Cats #255

Sometimes, The Hero will discover an incredibly powerful weapon, tool, or piece of information, that was once made out to be a big deal; maybe it's a big secret, maybe it does something that had been thought to be impossible, like kill an unkillable enemy, and it usually requires a whole lot of effort to obtain. In any case, having it is an ace up the Hero's sleeve. The weapon/tool/resource is hyped up as a be-all, end-all game-changer. But immediately after it is used for the first time, it keeps appearing. Constantly. And not just in the hands of the Hero, not at all. If it is a weapon, other people find a way to make a replica with the same effect. If it's a tidbit of previously Classified Information, suddenly every villain and their grandma are aware of it. Everyone suddenly remembers the secret of what was supposed to be a long-lost Infinity Plus One Sword, with no visible effort on their part; once the Hero has gone to all the trouble of obtaining it, other characters seem to pull their own versions out of thin air. Everyone Has A Power Ring does not diminish the effectiveness of the weapon, but it does destroys the hype that was built up around it by filling the story with other such items capable of all the same things.

The item in question can serve a dual role for the Hero as a Sword of Plot Advancement, but the drama surrounding it does not dissipate until it is actually shown that Everyone Has A Power Ring. This drama can reoccur if it's also the Achilles Heel of a major villain.

This may be that rare moment where the Super Prototype wasn't affected by No Plans No Prototype No Backup.

Everyone Has a Power Ring differs from the Sword of Plot Advancement because a broad range of characters have sudden and complete access to the item. See also Kryptonite Is Everywhere, Infinity Plus One Sword, Sword of Plot Advancement. Compare and contrast So Last Season and Continuity Drift. For the character counterparts, see The Worf Effect, The Chosen Many, and Everyone Is a Super. In video games, the opposite of this is Commonplace Rare.

Anime and Manga

 * In the first season of Code Geass the Hadron Cannon was an experimental weapon capable of destroying a small army, and only the Knightmare Frame Gawain had it; at the same time, it was one of only three Knightmares with the ability to fly. By the second season there had been a one year Time Skip, however, and suddenly a bunch of Knightmares had Hadron Cannons equipped, and by the end there were barely any Knightmares that couldn't fly.
 * Takes a turn for the bizarre in the finale, when one of the Knightmares flying around is clearly a Portman (a dedicated Knightmare submarine).
 * Stands in JoJo's Bizarre Adventure started as the psychic manifestation of a very strong willed person, but when the Bow and Arrow are introduced, everyone and their mother, no matter how pitiful a person, could have one.
 * Gurren Lagann: You stole a giant robot, making you the most dangerous humans on the planet? Good idea; now we've all done the same in imitation! What, now you've learned to combine them and wield superhuman power? We'll all start doing that too!
 * It took Goku a lot of time to become the legendary Super Saiyan in Dragonball . A few years down the road, all of the series' saiyans have not only reached that level, but surpassed two, three or even four times.
 * Lampshaded by Vegeta when he learns that his 8 years old and Goku's 7 years old sons are both able to do it.
 * In Digimon Adventure, the 8 Chosen Children were the only people with digivices and digimon partners. It appears now that, in Digimon Adventure 02, there are hundreds, or maybe thousands of chosen children all over the world, each with a digivice and a digimon partner.

Comics

 * In the original run, the Green Lantern Ring was a big deal. Just having it made an Earthling one of the most powerful beings in-continuity. Then Continuity Drift happened, and there were hundreds of Green Lanterns, and calling the human who had one "The Green Lantern" seemed rather silly. Then, there were several humans who had one, at the same time, in direct conflict with the established distribution method. Then we found out that there were other Lantern Corps of various colors. Slowly, the Green Lantern Ring was necessary to be even marginally effective in related conflicts, and some characters who have them still can't hold their own.
 * Kryptonite in Superman comics. At first it was an incredibly rare mineral to use against the otherwise invulnerable Superman. Then, gradually, everyone and their mother acquired a piece of it, and the same time various forms of differently-coloured Kryptonite that did different things to Superman started to pop up, and all this lead to Kryptonite Is Everywhere. Then the writers, probably realizing the problems that come with this trope, got rid of Kryptonite altogether. That didn't last though, as the idea of Superman having an Achilles Heel in Kryptonite was considered too valuable to discard permanently.

Film

 * Iron Man 2 averts this. At Tony Stark's tribunal, video clips are shown of hostile competitors attempting to develop their own power suits. They fail hilariously.
 * In the same film, Justin Hammer commissions a few hundred of these from Ivan Vanko to sell to the military, and they work great, . Even so, Vanko is the only one capable of replicating Tony's work (because Vanko's father helped Tony's build the arc reactor.)
 * Vanko is in essence, Tony's dark mirror image in both personal history and personal ability. After all, who else but Evil Tony Stark could build his own suit of armor, including an independently developed Mini Arc Reactor and Energy Whips IN AN APARTMENT! WITH A BOX OF SCRAPS!

Live Action TV

 * Supernatural used this with the introduction of the Devil's Trap at the end of Season One. Apparently Sam and Dean, two of the most experienced hunters out there, not to mention their father, didn't know about a magic chalk circle which could trap demons. As soon as Bobby uses it, suddenly everyone with even basic awareness of demons can make one, and it starts appearing everywhere as a primary security measure.
 * The Stargate is a wondrous piece of technology on which the fate of humanity rests when it is first found, only to become increasingly trivial as time goes on; by the end of SG 1, Earth has had at least 3 stargates.
 * Stargate is full of this trope. Amazing and unique devices that wowed and shocked us three episodes ago are now commonplace. One of a kind cloaking devices? Now comes standard on every model. Fast hyperspace travel? Every little podunk space ship has got one. The list could go on. This is mostly justified in universe as Humans Are Special, or more specifically, the Tau'ri are special and every other culture is static, and that the whole point of the SG teams going out into the universe is to acquire tech, which, sort of somehow ends up in the hands of everyone... This is good in the sense that Earth develops technologically over time, becoming something of a superpower, thereby avoiding the Reset Button plaguing many science fiction universes. On the other hand, it leads to massive power creep.
 * Stargate Universe has its own little odd twist: the Icarus base required the power of a planet with a ultra-super rare one of a kind naquadria core. They've found at least 2 more compatible planets already.
 * Early on in Hercules: The Legendary Journeys and Xena: Warrior Princess, there was only one thing that could kill a god; the blood of the Golden Hind. By the time both series ended, there seemed to be a new way to kill a god every week.

Video Games

 * In Pokémon games, each generation is released with new legendary Pokemon, which are meant to be one-of-a-kind and incredibly rare. At last count, there are 48 of them, with fourteen of them being released in Gen IV alone.
 * This will also lead to a meta-example: Every single player knows where every legendary is, knows it's a Game Breaker, and (ab)uses it. So it's entirely possible to have a four-player Mewtwo and Mewtwo vs. Mewtwo and Mewtwo match.
 * Kingdom Hearts introduced the Key Blade, a weapon that can open or close the heart of worlds, can't be stolen from the wielder, and can appear from Hammerspace. Only The Chosen One can wield it, but it turns out there were two chosen ones, and Riku giving into the darkness became a major dilemma since Sora had to fight his better and opposite. Then it turns out King Mickey is also a chosen one. Also Kairi. By the time of Birth By Sleep, it turns out there was a whole slew of them, at once!
 * For the first two Metroid Prime games, phazon is a rare and mysterious substance, and the space pirates go to great lengths to secure sources of it; but in Corruption, phazon is everywhere. It's reasonably justified in many cases in that phazon has been weaponized and thus heavily adopted by both the space pirates and the Galactic Federation as part of the interstellar arms race, and that phazon is found in the environments because the pirates are deliberately trying to spread it everywhere and it's pretty good at spreading itself anyway. However, it stretches disbelief a bit that every other random indigenous alien space monster now runs on phazon (according to the scan data), when they've only been exposed to it for a few weeks.

Tabletop Gaming

 * High-level magic in most Tabletop RPGs could qualify. By the time your D&D character learns Power Word Kill, (s)he's already fighting enemies who are powerful enough to know it too.
 * Every high-level Magic the Gathering constructed tournament has approximately three decks (anything else is generally looked upon as a "rogue" deck):
 * The deck with the super-powerful card of the moment;
 * The deck designed to combat the super-powerful card of the moment; and
 * the deck designed to beat that deck, banking on the numbers game to try and avoid deck 1.
 * Almost always, said super-powerful card of the moment will be a four of in all the decks that have it, despite costing a lot of money to procure one of them (either ripping open packs, or buying them on the secondary market).

Mythology

 * In Greek mythology, Zeus tried to prevent this by keeping the secret of fire exclusive to the gods. Prometheus stole it and spread the gift of fire to the entire human race.

Real Life

 * A popular saying runs, "God made man, but Sam Colt made men equal." Prior to the revolver, handguns were expensive, inefficient, and inaccurate, but Colt managed to develop the relatively inexpensive revolver. The result was personal firearms becoming much more common.
 * Nuclear armaments fit into this. During WWII, only a few countries were trying to split the atom. After the atomic bombings of Hiroshima and Nagasaki, and the capability of nuclear weaponry became realized, more and more nations scrambled to get their own nukes ready. Now, a lot of countries have weapons capable of vaporizing cities which nobody wants to see in action, and the existence of nukes forces diplomatic resolution of conflict, or at least smaller-scale armed conflict.

Webcomics

 * Justified in Schlock Mercenary with the teraport. Kevyn invents the technology and before too long everyone has it... because they spammed half the galaxy with the specs to prevent the idea being suppressed. Also unusual in that the consequences of the sudden proliferation of this new technology are also explored.
 * Zig Zagged in Darths and Droids with lightsabers, which everyone refers to as "laser swords". At first they're assumed to be some cheap, low-level trash that the protagonists apparently bought in a bar. Then Jim gets the idea to use them to deflect blaster attacks, which allows him and Ben to curbstomp a squad of droids they were supposed to have no chance against. This trope then gets inverted when it's said that only Jedi carry lightsabers, only to be played straight later when  is shown to be carrying one as well with no explanation.