019. The Gate of Destiny (II)

The general plot unfolds as follows: The Future Gadget Laboratory, a trio of inventors based in Akihabara, is led by Rintaro Okabe, a Tokyo Denki University freshman who cannot shake off his chuunibyo tendencies. Day after day, Okabe and his companions immerse themselves in devising bizarre inventions.

On July 28, 2010, Okabe attends a lecture with his classmate and friend, Itaru Hashida, hoping to earn some credits. There, they encounter Kurisu Makise, a prodigious girl who, at only eighteen, has already published a paper in an American scientific journal.

Yet, something strange has already occurred: just hours before, Okabe witnessed Kurisu lying in a pool of blood, collapsed on the eighth floor of the RADIO Building. What makes it even more perplexing is that every detail of these events was clearly described in a text message Okabe sent to Hashida a week prior.

Eventually, Okabe discovers that one of their inventions inadvertently possesses the ability to send text messages to the past—in essence, it functions as a time machine.

At that point, Okabe never imagined that this accidental invention would become the key to the world's future, heralding the birth of a monumental discovery.

In his previous life, this work was regarded by many as a masterpiece, though some found it confusing and impenetrable. Regardless of one’s comprehension or patience, everyone was undoubtedly astonished by the way this game popularized the concept of “world line convergence theory” among its players.

Much like Jiang Yu had always heard of the legendary “The Three-Body Problem” and was familiar with the “Dark Forest Theory,” it wasn’t until he read the novel himself that he was left deeply stirred and unable to calm his emotions for a long time.

The so-called “world line convergence theory” posits that different world lines ultimately converge to a common outcome.

A single world contains countless branching possibilities—world lines. The world system within the SG universe can be likened to a quantum system in an entangled state, referred to here as a world line entanglement state. Countless possible world lines are interwoven, forming a convergence zone, and numerous convergence zones together create even larger convergence zones, resembling a spindle-shaped structure like 1-2-4-8-16-32-16-8-4-2-1.

The specific state of a world within this entangled web is determined by the observer. It is crucial to note that, due to the presence of the “observer,” the different world lines in SG exist in a cycle of construction, collapse, and reconstruction—a single-universe theory, not a parallel-universes theory.

This is the issue Kurisu deliberately avoids in the “Dissolution of Causality” chapter when she sacrifices herself to prompt the protagonist to let her go. She will not survive in another parallel world, for in the perception of the observer—Kyouma Hououin—Kurisu Makise is already dead. This renders the choice all the more tragic.

This single universe resembles a quantum superposition of particles, containing “infinite possibilities.”

Here, it's worth mentioning the classic Copenhagen interpretation familiar to all: “Schrödinger’s Cat.” Observation determines the cat’s fate; before observation, the cat remains in a superposed state of both life and death. Because we do not know the future, the outcome—life or death—must eventually converge.

Because of the observer’s existence, an event can have only one definite outcome, though the result depends on the observation. There are countless possibilities superimposed for the same event, but only one will solidify into reality.

Simply put, if you are being observed, and the observer knows you must die but is trying to prevent your death, fate will intervene. If you dodge a falling steel beam, the laws of nature may interfere, and next time you might die from exposure to a live wire.

It’s a little like “Final Destination,” except without the supernatural element—the entire theory is grounded in relativity, quantum mechanics, and M-theory.

Just like in the game, where Rintaro Okabe repeatedly travels back in time to prevent Mayuri Shiina’s death, striving to change her fate, he ultimately discovers his efforts are futile. No matter how many times he returns to the past, in his perception—and the world’s—Mayuri’s death on that world line is inescapable.

What makes “Steins;Gate” remarkable is that it does not bombard you with the theory upfront; instead, as players follow Kyouma Hououin’s perspective, they gradually deduce this through repeated attempts to save Mayuri, deepening the sense of unraveling a mystery.

So, after we witness, through Kyouma Hououin’s eyes, Mayuri’s death time and again, endure countless journeys to the past, see the “failed” notes filling entire pages by the warrior part-timer, the sacrifice of Luka’s wish to become a woman, the sacrifice of Faris’s wish to be with her father, and ultimately even the sacrifice of Kurisu Makise’s life—all to resurrect Mayuri—an overwhelming sorrow arises.

And in the end, as Kyouma delivers his manic victory speech and Mayuri gently says, “It’s all right now, little Okabe, you can cry for yourself,” the sadness is truly beyond words.

Yet sacrifice does not bring ultimate victory—that is the tragedy of the game's sacrificial endings. Sacrificing Mayuri leads to the world being controlled by SERN, creating a false utopia; sacrificing Kurisu triggers a military arms race, igniting a world war that decimates humanity.

Thus, Kyouma Hououin begins his search for the true “Steins;Gate” world line, where both Mayuri Shiina and Kurisu Makise survive.

The journey itself is deeply intriguing, even featuring a future Rintaro Okabe from the world line where Kurisu died, reaching back to guide his past self.

“Don’t change the past where Kurisu Makise ‘dies’ to save her,” he advises—deceive your past self, change the outcome without altering the established facts.

These ideas subtly resonate with modern quantum mechanics, like “Schrödinger’s Cat,” where the observer’s subjective impression and the observed’s objective state seem mysteriously linked, not truly independent.

To summarize the “world line convergence theory” in “Steins;Gate”:

First, convergence occurs after a major divergence point, triggered to ensure the necessary future.

Second, the world thwarts any action that would alter the outcome; this is the convergence of world lines. Events that are “the result” will inevitably transpire.

Third, causality determines the priority of convergence.

Finally, the form convergence takes is unlimited; this is the law of nature (or God), and any event within these laws will interfere with convergence.

In the Steins;Gate world line, the established fact of Kurisu Makise’s survival contradicts Rintaro Okabe’s perception of her death; here, the former takes precedence. In the world line where Okabe perceives Kurisu as dead, Mayuri Shiina’s image for Okabe—the observer—is that of survival.

Thus, following the theory of the future Rintaro Okabe, the present Okabe finally steps into the true “Steins;Gate” world line, where both Mayuri Shiina and Kurisu Makise survive.

Of course, all these explanations stem from the game itself; in reality, the “world line convergence theory” remains unproven and unfalsifiable.

In Jiang Yu’s current world, the theory of parallel universes still prevails, and although some have proposed the “world line convergence theory,” it attracts little attention.

Jiang Yu believes that even stripped of the traditional galgame elements—harem, cat maids, traps, tsundere flat-chested girls, busty heroines, the friend’s daughter, or even, yes, the much-maligned “otaku”—Steins;Gate, as a work of hard science fiction, would still strike the stagnating gaming world like a thunderclap.

Moreover, cloaked in this form and released as a galgame, not only does it allow the text to provide deeper exposition with less workload (and that, of course, is the main point~), it also draws the attention of otaku who would otherwise ignore such topics entirely.

And as for the promotional power of dedicated fans when it comes to a beloved work... Even Eru Akiyama would have much to say.