Sword Art Online frequently makes reference to many other media. You will need to keep an eye out for them whether you're reading the novels or watching the anime.
- The boxes for NERV Gear games like SAO look like the ones for PlayStation 4.
- Someone cosplaying as Wally can be seen queuing to buy SAO in episode 1.
- Kikuoka apparently watched an anime where everyone in real life suffered epilepsy around the country. This is, of course, referring to the now-banned Porygon episode.
- In the Calibur Arc, When Yui is explaining the Cardinal Systems quest generation a clip of The Ring and Friday the 13th can be seen.
- Towards the end of the Anime, Kirito kills Oberon by stabbing into the sky at him in a scene very reminiscent of Gundam's Last Shooting.
- Speaking of Gundam, watch the scene in which Kirito, Leafa and the Sylph/Cait-Sith alliance break through the Guardians. The Cait-Sith's dragons wipe out a number of them in the same left-right pan as the remastered Freedom Gundam at JOSH-A, and the Sylphs' Sword Beams hit with the same shot composition and camera movement as the Strike Freedom's dragoon-enabled Full Burst.
- While going through a tunnel under a mountain, Kirito mentions to Leafa a book that he read in which the party also went under a mountain, only to be ambushed by Orcs and then meet an ancient demon. Moments later, they are ambushed by a bunch of Salamanders. Just when they're about to lose, Kirito transforms into a large demon engulfed in flame and tears apart the Salamanders, including some wizards.
- The photon sword in the Phantom Bullet arc is clearly intended as a Star Wars Shout Out, and Kirito is inspired to cut bullets thanks to seeing Jedi deflecting blaster bolts, though if he had read anything from said franchise's expanded universe he probably wouldn't have tried.note The small droid that brings the item to him could also be a shout out to R2-D2 from the same series. In the anime, the photon sword even uses the same sound effects as a lightsaber. In the light novel, Sinon even points out that some call the "lightsabers" by name.Sinon: The official title is "photon sword," but everyone just calls them laser blades, or lightsabers, or beam sabers, or whatever they want.Kirito: S-swords?! There are swords in this game?! (narrating) I leaned over to get a better look at the case. Now that she'd put the image in my head, they did indeed resemble the tools used by those force-wielding knights in the sci-fi movies of old.
- The beam saber is also purple, which could be a reference to Mace Windu. This would make sense given that, just like Kirito, Mace Windu is known in his own universe for being an absolutely impossible badass at sword combat — even by the standards of his peers.
- There's also the fact that the Arc Villain, Death Gun, is a Darth Vader Expy, making the Star Wars analogy even more fitting.
- Mention is made of Subtilizer, aka Gabriel Miller, an American GGO player who won the first BoB tournament with only a pistol and a combat knife, alternating shooting with knifing — a common build in Call of Duty: Modern Warfare 2 (the leader Sinon is with in the beginning of the anime goes "Go! Go! Go!"). Subtilizer, in a later tournament, uses CQC to disarm his opponents and grab their weapons, strongly invoking the first Metal Gear Solid 4: Guns of the Patriots trailer, where Old Snake does precisely that.
- One random quest in SAO involves players hunting monsters wearing leather masks and carrying chainsaws.
- In Episode 1 of the anime, when Klein attempts to log out, he performs Kamen Rider 1's henshin pose.
- The skinny guy of the Fat and Skinny duo seen in episode 1 is a G.I.R.L. resembling Haruka Amami.
- One gameplay element in GGO is a bullet path indication, where the HUD displays a green line (red in the anime) leading back to whoever is shooting at you, reminiscent of the "Threat Tracer" upgrade for the Nanosuit in Crysis 2. In addition to this, the anime shows that the game accounts for wind speed, gravity, and humidity, and when a player gets a shot the camera follows the bullet, all of these similar to Sniper Elite.
- The wire-frame & vector shaded lead-in to each episode (or at least Episode 2) has some pretty clear allusions to TRON.
- Kikuoka mentions a certain movie while explaining Project Alicization.
- Cardinal's assistant is a little spider named Charlotte. Does that ring a bell?
- In the anime, the entrance of the 74th floor dungeon is the same as the entrance to the place where the Holy Grail was kept in Indiana Jones and the Last Crusade; alternately, it's where the Primes were buried in Transformers: Revenge of The Fallen — the ancient city of Petra
. - One underground dungeon in ALO strongly evokes Skyrim's Blackreach in its environment and design.
- The green water bottles that show up occasionally in the anime (first at the table Asuna and Kirito eat at during the murder investigation in Episode 5, and again when Kuradeel poisons Kirito and Godfree in episode 10) are dead ringers for Skyrim's Alto Wine bottles.
- The Light Novel illustrations of Yuuki's battledress show it's essentially a recolor of Saber Lily's dress.
- A chat between GGO players in the anime takes place on a live Nico Nico Douga-esque stream. Among one of them is an avatar that suspiciously looks and poses like a Cactaur.
- In Episode 4 of Phantom Bullet, one player who is amazed by Kirito's bullet-dodging skills in the "Untouchable" mini-game looks is a bald guy with an arrow tattoo on his forehead.
- In Episode 7 of Phantom Bullet, we see a truncated list of the players in the BoB tournament. One of them is named Jack Reacher. Also a case of irony, since that character actually tends to refrain from using guns when not absolutely necessary.
- Another one of them is named JIGEN.
- Some of the players are named after members of the forum for the site where Reki Kawahara originally posted chapters for novel back when it was simply a web-novel.
- Then in Episode 8, one of the players in the BoB tournament is named Lion King Richie. The Japanese word for "king", "oh", sounds almost like "el". So you've basically got Lionel Richie. It's also a reference to ThunderCats' main character Lion-O.
- Kirito is referred to as the "The Black Swordsman" due to having black hair, wearing black and his main weapon being a black sword. Of course, this is one Shout-Out that got a little too heated in some circles...
- In Hollow Realization, there's another player running around by the name of Genesis who also goes by the moniker of "The Black Swordsman", and perhaps not coincidentally he uses a BFS, is a loner, can be quite the jerk, and uses a dangerous power-up in order to win his biggest fights. Ironically, he's seen as a "pretender" in-universe in much the same way that Kirito was seen as such by out-of-universe fans.
- Neon Genesis Evangelion shout outs:
- The gear worn to participate in the Sword Art Online experience - In-Universe - is called "Nerve Gear" (without it, there is no show); in Evangelion, NERV is the name of the singular organization by which Shinji may interact with the Angels (without it, there is no show).
- Asuna: a redhead who wears her hair in the most peculiar way of the female cast and who also becomes the protagonist's primary love interest; finally, she's revealed to be in a coma in the second half of the first series. Compare her with Asuka — Asuka Langley Soryu.
- Near the end of the first season, they meet an incredibly intelligent and immune A.I. character, who can only exist within the virtual reality of VRMMORPG: she behaves exactly like a human, but technically isn't; she pleads with Asuna and Kirito to be her surrogate parents (the former a direct shout-out, and the latter an inverse shout-out to Rei Ayanami); finally — alongside her limited existence within artifical reality — her name is Yui (both direct shout-outs to Yui Ikari).
- At the end of Season 1, we learn the creator of the game is an eccentric, enigmatic man so dedicated to his work that suicidal thoughts motivated his creative choices, to the point that he valued his work more than his life. The product of his efforts is now remembered by those who used it as a valuable, affecting experience adding to the value of real life.
- Episode 22 details Asuna's attempt to escape from her birdcage prison; as she attempts this, tentacle-monsters capture and man-handle her; in Episode 22 of Evangelion, Asuka is mentally raped by an unprecedented monster — the Angel Arael. Both episodes highlight the expectation of Fanservice from their Otaku audience.
- While attempting to solo the Grand Quest, Kirito gets overwhelmed by a swarm of enemies, ending up impaled multiple times, similar to Asuka's fight with the Mass-Production Evas in End of Evangelion. There's even a similar POV shot of Kirito futilely reaching skyward, in his case towards the upper levels of the World Tree where Asuna is being held.
- In Episode 4 of Series II, Sinon leads Kirito through the world of Gun Gale Online, and takes him on an escalator ride that is an identical shot setup to one of the several instances Shinji and Rei travel the escalators inside NERV HQ.
- In Phantom Bullet Episode 8, Kirito and Sinon have an Uncomfortable Elevator Moment that starts off◊ looking exactly like Evangelion's infamous Leave the Camera Running scene.
- In Episode 13 of Series II, while speaking with Kirito and Sinon, Kikuoka strikes Gendo Ikari's signature pose, complete with Scary Shiny Glasses — they are almost identical.
- While we're at it, Sinon's real-life appearance looks a lot like a younger Mari Makinami Illustrious.
- Megumi Hayashibara — who voiced Rei Ayanami and, more importantly, Yui Ikari (Shinji's mother) in Evangelion — voices Asuna's mother, and, in keeping with Evangelion's core emotive, this mother's presence immediately vexes Asuna. Also, her name is Kyoko, as in Asuka's mother Kyoko Zeppeli.
- Ramiel — hostile Angel through episodes 5 and 6 in Evangelion — is the camera and cameraman for a group photo of the members of the "Sleeping Knights" guild in Episode 22 of Season 2.
- Sachi's posthumous recording crystal also takes the form of said angel.
- In Alicization Awakening, Suguha takes a grievous injury while battling as goddess Terraria in Underworld in the form of a spear through the eye, much like Unit 02 getting stabbed through both eyes with the Lance of Longinus. The anime adaptation even adds a massive burst of High-Pressure Blood just like how the Unit bleeds.
- In Alicization Lasting, after Niemon's battery cable takes massive damage from Hans's gunfire, it shuts down... but after Rinko screams at Kayaba to wake up, its systems reactivate and one of the Rath technicians exclaims, "Unit 02 has reactivated!" just like in End of Evangelion when Unit 02 reactivates after its battery cable is severed for its final battle against the mass-produced Evas.
- One scene in Ordinal Scale takes place in a Wagnaria!! restaurant.
- The film producers also confirmed that Ordinal Scale has some references to the Digimon film Our War Game.
- The main character (Ta'ichi and Kirito) buys a gift to the redheaded female main character (Sora and Asuna). However this similarity ends when Sora ends up with Yamato anyway, while Kirito x Asuna are the Official Couple in SAO.
- The main characters enter the cyberspace again to defeat the Final Boss. Again, some differences: Ta'ichi and Yamato are close to Heroic BSoD when the boss has defeated War Greymon and Metal Garurumon; while Kirito & Co are about to fight the Incarnate, with Asuna joining in later as part of the Big Damn Heroes.
- Both films have a climax that, if the heroes don't prevail, will have serious repercussions: an American nuclear missile flattening Tokyo in OWG, and in Ordinal Scale the Tokyo 2020 Olympic stadium turned into a giant NerveGear, with the Ordinal Scale drones frying the brains of all Augma users inside, Kirito & Co included.
- Somehow the Shimane Prefecture is involved. Suguha goes to Shimane for training camp. In OWG Yamato and Takeru visit their grandmother there too, and they have to go a long distance to find a computer in her village to follow the battle in cyberspace.
- Also, the main character's little sister is absent for most of the plot. Hikari is attending her friend's birthday party, while Suguha/Leafa, as mentioned, is in training camp, although she does make some appearances, helping train her brother via video chat, joining in the fight against the Incarnate, and being at the party celebrating Ryoutarou/Klein's discharge from hospital.
- The movie Aria of a Starless Night features Tekken 7 as a fighting game that Misumi/Mito plays. In a flashback where Asuna finds Misumi playing at the arcade, the latter can be heard yelling "Ora" repeatedly while mashing buttons.
- During Volume 10, Kikuoka, while explaining to Asuna that it isn't possible to create a facsimile of modern society in virtual reality, hence why Underworld is set in the medieval times, Kikuoka all but mentions The Truman Show by name ("a movie from before (Asuna was) born"), while discussing that the protagonist "starts spotting the cracks and eventually realizes the truth…”
- Gabe's death is reminiscent to how Kira dies in JoJo's Bizarre Adventure. Both characters arrive somewhere other than they thought they should be (Gabe in the STL room, Kira at the haunted alley), only to encounter the girl they killed years ago (Gabe killed Alicia, Kira killed Reimi) and get Dragged Off to Hell by the souls of the dead. And both are villains of their respective story arcs.
- Episode 14 of Alicization has a huge visual reference to Fate/stay night [Unlimited Blade Works] with the scene where Kirito uses Spinning Shield to blocks Deusolbert's Conflagration Bow◊ is near-identical to Archer using Rho Aias to block Lancer's Gae Bolg◊.
- Alice's line during the Rath press conference in Volume 18 about opening up her skull to prove she's an AI is referencing Terminator 2: Judgment Day when the T-800 removes the skin off his arm to prove to Miles Dyson it's a machine.
- Along those lines, episode 10 of Series II shows Kirito and Sinon looking back at a small inferno, exactly as John and the T-800 did in the canal chase scene.
- The duo adorable yet eerily out-of-context little girls that Kirito and Eugeo encounter on their ascent up the 100 flights of red-carpeted stairs of Quinella's tower is a nod to the Creepy Twins of little-girl ghosts encountered by Danny in the 1975 Stanley Kubrick horror film The Shining
- The epilogue to The Alicization Arc, wherein Kirito and Asuna spend centuries as King and Queen of the Underworld that they saved, only to forget about all of it when they return to the "real" world, so they can readjust and normally live out the rest of their mortal childhood is almost identical to the what happens to the Four Pevensie Children protagonists of The Lion, the Witch, and the Wardrobe after their adventures in Narnia.
- During the Prologue of the Unital Ring arc, which reveals Kazuto's original surname (Narusaka), Kazuto himself wonders that had his parents still been alive up to that point, he would have named his online persona Naruto (Narusaka Kazuto).
- In Memory Defrag:
- The event, "Support Mech, Ultimate Duo", when the SAO gang are worried about fighting against Epidanthia, Leafa comments that "her power level must be well over nine thousand!"
- In the character event "To Each Their Own", when Kirito is explaining to Sinon of the reach of close range weapons, he remarks the only weapon capable of the range of the bows she was used to would be Goku's Power Pole.
- In Integral Factor
- The 2019 April Fools event had Kirito and Asuna turning into little kids and dressing as detectives. Yuuki even dresses as a Phantom Thief, while Asuna's skill record comes with the tagline "There's only one truth!"
- In Fatal Bullet:
- During one of Agil's events in which he ropes the Player, Kirito, and Klein into modeling some post-Apocalyptic armor he's found and wants to sell. Kirito ends up wearing Max Rockatansky's armor.
- In the Ambush of the Imposters DLC, Yamikaze, the de facto leader of Zeliska's contact team, wears armor that sports an interesting grey, red, and white color scheme that is rather similar to a certain other commander from a third-person sci-fi RPG franchise.
- During one of Arfa-Sys's Affection Events, they at one point quotes "This burning fist of mine is glowing red! It screams at me to destroy my enemies!", subtly referencing part of Domon Kasshu's famous quote "This hand of mine glows with an awesome power! It's loud roar tells me to defeat you! Take this! My love! My anger! And all of my sorrow! Erupting... God... FINGER!"
- War of the Underworld ends with a message saying "Kirito will return", similar to James Bond or the Marvel Cinematic Universe.
