Canon Shadow

A character or item that is to be in the Player Party or inventory, but other than being able to hit enemies and have stats, it has no effect on the plot. It looks like it's there, but for most effects and purposes, it isn't. Especially odd when its very existence should be a big deal. A form of Gameplay and Story Segregation, this is a cross between Player Mooks and Schrodinger's Cast. This tends to be excusable as many of these examples are actually optional.

Canon Shadows are often the result of New Game+, DLC and other tricks (hereby refered to as "Shenanigans"), but can also result due to simple plot restrictions.

Even (and especially) when it should be huge.

Examples of Types of Canon Shadow:
 * 1) That member of the Player Party who should at least have knowledge of the plot or a very strong reaction with the plot; and yet nothing happens, either from them personally or from people who see them. (This does not count if they're intentionally being unhelpful.)
 * 2) That Sword of Plot Advancement gotten early through Shenanigans but doesn't advance the plot until you go through the motions of getting it in a cutscene.
 * 3) That character who died a Plotline Death on whom you used Shenanigans to get them Back From the Dead; yet you still talk about how he died.
 * 4) You can also gain certain party members sooner than the plot dictates, and if they're gained in the plot via Defeat Means Friendship, use them to fight themselves.
 * 5) It is the enemy's singular Artifact of Doom or Evil Weapon that you have acquired through Shenanigans; it doesn't corrupt you and the enemy also has his own version.

Justified because it's Rule of Cool to have them in gameplay; but to actually have it change the plot would drive things Off the Rails. A Dream Match Game is pretty much when every character is like this in terms of the overall series timeline/mythology.

Video Games
"Kal'Reegar: We talked on the radio before the dropship arrived...YOU'VE GOT A GETH RIGHT BEHIND YOU!
 * The reward for getting all the stars in the initial run of Super Mario Galaxy? You get to play as Luigi! ....And do all the missions over again, including the ones where you rescue Luigi. When playing these levels, there is a Luigi "clone" wherever Luigi would be rescued in a Mario playthrough.
 * In the Resident Evil games, the One-Hit Kill Rocket Launcher usually appears as a Deus Ex Machina to kill whatever the Final Boss is. There may be a way to get it sooner; usually via New Game+; but while it's "the strongest weapon", it does not kill said Final Boss whenever he appears earlier in the game as a Hopeless Boss Fight.
 * Resident Evil 4 kind of averts this: the special rocket launcher you get is specifically called the "Special Rocket Launcher", and is described as having enough firepower to obliterate the final boss. That being said, it can't have more power than an infinite number of normal rockets, which you can get on subsequent playthroughs.
 * Fate Unlimited Codes has a version of Saber called "Saber Lily". This is a version of Saber where Britain accepted her gender; and she kept her first sword Caliburn. This should radically change her character; but there is no sign that she's different in personality from the original Saber.
 * Word of God even refers to her as a "Refraction of the Kaleidoscope."
 * In the second playthrough of X Box Ninja Gaiden, one can find the Dark Dragon Blade if you know where to look. The villains still have their version; nobody thinks of trying to steal yours.
 * Lampshaded in Nie R. As part of a story event, a smith gives you a broken sword and promises to fix it. He does this again on a New Game Plus, which carries your inventory over. Nier asks if he doesn't have it already. Weiss just tells him this is how things happen the second time through.
 * In the Soulcalibur series, one can unlock the Soul Edge as a weapon for any character. It may have a negative effect like random stats or depletes your HP, but it does not drive you crazy unless your character actually uses it in a cutscene. In some endgame cutscenes, it's possible to watch your character use their Soul Edge that you unlocked to destroy the Soul Edge dropped by the final enemy; or throw their Soul Edge away and pick up the other; and get corrupted.
 * Common in Nippon Ichi games; many of the DLC or Cameo characters who join the party have no effect on the plot; no matter what their previous experience is.
 * Adell is the only human being in Veldime! Except for, you know, those humans that his sister summoned. But they don't count, nor are they turned into Demons by the Curse.
 * Justified Trope in Phantom Brave and Makai Kingdom, where certain characters' shadows join your party as phantoms; while they themselves do not. (Lampshaded by Ash in The Hermuda Triangle; in gaining the future astrally projected soul of Castille who is stuck in Makai Kingdom. "Um...won't this affect the future?")
 * Similarily in Soul Nomad and The World Eaters, where defeating secret characters such as Asagi and Lujei adds them to your roster but never includes them in cutscenes... because technically you only have their manikin, and they only appear when you forcibly summon them for battles. Outside of battles, they're likely somewhere else, doing their own thing, just like every other recruitable character.
 * Soul Nomad does have a version that even it can't justify, though: If you beat him as a Bonus Boss, you can get Median the Conqueror as a party member. Even if you can only summon him for battles, his presence on the battlefield should have a massive impact on the plot and should prompt immediate reactions from numerous characters, yet is totally ignored. And, of course, you can use him to fight his future self.
 * Cla Dun is this trope, pure and simple, as its character create system/editing allows you to have any NPC as the main character or Player Mook, even the one who died in story.
 * Special codes in Valkyria Chronicles II can let characters like Maximilian, Selvaria, and Isara join your party; despite being  There isn't even a Hand Wave justifying this. Naturally nobody reacts to the previous Imperial Prince and his champion fighting for Gallia.
 * There's also other characters from the first game; who are explicitly stated by the plot to be staying out of the Gallian Civil War to prevent a diplomatic issue; but that's a smaller wonk than the above.
 * Even without codes, after you get enough medals,  join your party, and they
 * It gets more ludicrous in Valkyria Chronicles III. You can get Aliasse via password, and she can . One of the plot points is seeking to eliminate Riela because she's an impure, you would think that having Aliasse in your squad will give you HUGE leverage.
 * Chrono Cross has a feature where in New Game+, you can pull all of the characters you had in your party whenever you had previously beaten the game; even the ones who are in contradictory path. While some might have a special attack or two; they do not interact. (Especially huge is being able to being Harle back.)
 * In the PSP Updated Rerelease of Tactics Ogre, there is a function called "The World System", similar to New Game+; it lets you take your characters back in time to any decision made and let's you pick a different choice and follow a different path. This allows for situations where you can have characters who joined your party in one timeline help you kill their alternate selves who opposed you in another in gameplay. Plotwise, though, you'll grieve the death of a character even with them still in your party.
 * In The World Ends With You, after you play the whole game, you can play with any Partner in whatever week you like. Even against themselves, or when you're fighting to save them.
 * One can regain the literal ghost of a character who sacrifices herself in Jeanne D'Arc, and the special cutscene where you get her makes it seem she can talk and such; but cutscenes have the characters indicate that this person is completely gone. Of course; you can't do this until you beat the game.
 * In Mass Effect 1, any new game Commander Shepard can learn any skill that you have an achievement unlocked for from previous games. It is possible to have a Assault Gun Wielding Biotic Shepard with Engineering skills, despite not being that class.
 * In Mass Effect 2, during Tali's loyalty mission, part of the space fleet that is Tali's home is quarantined to seal off an uprising of Geth, which are the mortal enemies of Tali's people, and charges are brought against Tali for bringing active Geth aboard the fleet. It's possible to unlock the Geth character Legion beforehand and bring him along for the trial. They react appropriately, but all it takes is some short bluster (apparently, the perrogative of captains to bring whichever of their crew along they like goes a long way in Quarian culture) before they stand down. Apart from a few strange looks and one snide comment during the trial, nobody else has a problem with it. This also happens if you bring Legion aboard the Citadel; his presence is acknowledged, but the security guard seems to think he's just a consumer-model robot assistant. Most players never encounter these incidents, though, as Legion is typically obtained right before the chain of events leading to the endgame begins - you actively have to go out of your way from the plot (and risk the circumstances) to take him anywhere.
 * Legion's presence is lampshaded during Tali's recruitment mission - when you join up with Kal'Reegar, he'll comment on Legion kneeling behind Shepard:

Legion: We are allied with Shepard. We will fight the Geth units in this area.

Kal'Reegar: You know, ordinarily that wouldn't fly with me, but I can't afford to be picky right now!"


 * Another example is the DLC characters, Zaeed and Kasumi. Occasionally they will throw in a comment about something, but they never make any major plot difference, unless you have them do something notable during the Suicide Mission.
 * Like the first game, any newly created Shepard can have one of a set of skills from characters he gained the achievements of their loyalty in previous games. This can include oddities like Dominate which only vampire mutant Asari can do.
 * And then there's the DLC which gives Shepard....a Collector outfit. You'd think THAT would get at least a funny look.
 * Justified, since a lot of people don't even think the Collectors actually exist, much less know what one looks like.
 * In Valkyrie Profile, two late-game bosses are directly responsible for two of your einherjar's deaths much earlier in the game. If you bring either of these characters into the battle with their killer, neither will say anything.
 * Mostly averted in the second game. If you read their profiles, you'll find that most of the einherjar you can recruit knew at least one or two others, so if you put them into the party together, they'll have a brief conversation at the start of a battle. It's only "mostly," though, as some combinations that you'd expect to have these happen don't.
 * In Knights of the Old Republic, despite the Sith guards on Taris supposedly looking for Bastila, they'll never comment on her presence even when she walks past them in her Jedi robe wielding a lightsaber. Maybe they're just that stupid, which might explain why Malak so quickly opted to destroy the entire planet. In the second game, nobody will comment on Kreia following you, including the same Jedi Masters who are latter surprised when she walks up to them in the light side ending. It is hinted, though, that she uses the Force as a kind of perception filter.
 * More than just hinted - one cutscene reveals that she routinely hides her presence from your other partymembers, either for practice of for the evulz.
 * If you use a character enough in Recettear, you get their "True Card" which lets you have them in your party immediately in New Game+. This includes having them fight themselves in battles where they are originally antagonistic.
 * Averted with the DLC character Doctor Doom in Marvel Ultimate Alliance: playing as Doom in the final battle (against Doom) will trigger a short conversation between the two Dooms, where it will turn out that one of them is from the future.
 * And of course, bringing Deadpool into the boss fight with Deadpool results in an argument between the two of them.
 * The dialogue rich game Scarface the World Is Yours has Tony Montana talk about how he wants the Big Bad dead. He does this even after the Big Bad is dead.
 * In Mortal Kombat: Shaolin Monks, Scorpion and Sub-Zero are unlockable as player characters in the Story Mode. Unfortunately, neither of them actually has a storyline and the game jsut acts as if you're playing as default protagonists Liu Kang and Kung Lao, even when you're fighting Boss Battles against Sub-Zero and Scorpion.
 * The DLC characters in Mortal Kombat 9 play a similar role. While they all have Arcade Ladder endings, none of them contribute to the canonical story (Skarlet cameos in crowds a few times, Kenshi is called to fight at the end of one of the chapters but never directly seen, Rain is given a background cameo in The Cathedral stage, Guest Fighters Kratos and Freddy Kreuger add nothing at all to the plot).
 * A minor example occurs in Persona 3 Portable. The female protagonist's route includes an opportunity to prevent the Plotline Death of, instead putting him into a coma to justify his absence from the rest of the game up until the ending. While the direct references to the character being dead are edited out, the dialogue isn't altered enough to change the fact that everyone is still acting like he died, particularly when his best friend asserts that "he was a hell of a guy."
 * Of course, as the Convenient Coma page will tell you, it's never asserted that he will wake up from his coma, so for all intents and purposes he might as well be dead.
 * A lot of the allies you use in the Sengoku Basara games are examples of this: Once unlocked with one character, they can be used by any character in any story, and nobody bats an eyelid to their presence. While you can never use another copy of the currently used character as an ally, you can bring along an ally to a mission where you have to fight that very same character.
 * Arc the Lad: End of Darkness allows you to play as different characters using "character cards". However these characters have no impact on the story and can only be used in a limited set of missions.
 * In Chrono Trigger, after you get on your party, you can bring him into the castle of the kingdom he was previously at war with, and nobody will say anything. It's vaguely possible that nobody knows what he looks like, but their knights did face him personally in the past...
 * Of course, nobody says anything about your robot, either. And aside from your mother, nobody in the present cares about your talking anthropomorphic frog.
 * In Battle Moon Wars, saving  has this effect. After that, she goes through the remainder of the game not speaking even once and only having "lines" (read: ellipses) twice; once during Haruna's Rousing Speech that lumps her in with fellow vampire Sion, and then at the end when the game cuts to her and Len in the Tohno family dungeons.
 * Fallout 3 had this, but Fallout: New Vegas went some way towards ameliorating it. In the former, you could wander into no-ghoul-zone Tenpenny Tower with a ghoul companion, or into The Citadel with a Super Mutant, and nobody would bat an eyelid. In New Vegas, all your potential companions have their own storylines and faction alignments; for example, if you go into the Silver Rush with Cass, Jean-Baptiste will shoot her on sight.
 * In Metal Gear Solid 3, you earn The Boss's one-of-a-kind Weapon of Choice as a New Game+ reward for beating her, leading to you being able to fight her with it on replays. If you own it, the Voice with an Internet Connection characters will even comment that it makes no plotline sense for Snake to have it.
 * Metal Gear Solid 2 starts with Snake breaking his stealth camouflage upon landing on the deck of the Discovery. One of the bonus items that can be earned through the Dog Tag sidequest is the stealth camo; so Snake and Otacon will talk about how the camo is broken and how they can't use it any more, even if you have it in your inventory for basically unlimited use. Inverted with Snake's infinite ammo bandanna, a powerup he can earn through the Dog Tag sidequest, which he always owns in the story (yes - it's a weird moment) whether or not he earned the ability to use it in gameplay.
 * Metal Gear Solid Integral had a Very Easy mode in which the player starts the game with an MP5 (which is not found in the game world or owned by any other game characters under normal circumstances), a powerful, silenced submachine gun with a ludicrous amount of ammunition which makes the game a breeze. Your comrades will still remind you at every opportunity that due to the mission being a black op, it was critically important they sent you in with no weapons that could be traced back to you.
 * Star Ocean has plenty of these, given that the first two games revolve around the small set of compulsory characters. (Four in the first, two in the second) While they all do have their own subplots and do contribute to canon events, they mostly are just there to make commentary and have fun in the private events. Despite this, some characters are more "Shadow"-like than others. Thankfully, the remakes fix these, making them Ascended Extras
 * T'Nique in the first Star Ocean game was pretty much a Secret Character and had no private events. The PSP Version remedies this; although he's still pretty much a secret character overall.
 * Dias in The Second Story. Remedied in the PSP version.
 * Welch Vineyard. However, potentially justified given that she really is an optional character. She holds a bit more significance in the first game than the second, where she doesn't even speak up for plot events. Granted, she's intentionally supposed to be a secret character, she holds much more weight in the third and fourth games