I Warned You

"Sadlygrove: Yugo? Amalia? Piglet!Yugo: *Oink* Piglet!Amalia: *Oink* Sadlygrove: I wouldn't want to play the "I warned you" card... (deep breath) BUT I WARNED YOU!"

- Wakfu, "The Dragon-Pig"

A character is (sometimes, quite specifically) warned of the horrible things that can happen if they do Action A. They blow off the warnings. After the terrible things happen, The Cassandra then informs them they have no-one to blame but themselves.

"Alice: Do not take the Shmuck Bait. If you do, terrible things will happen. Do not tempt fate. Bob: What's the worst that can happen? (terrible things happen) Alice: I Warned You."

That statement, whether or not it uses the Stock Phrase "I Warned You" or "I Told You So" is this trope, provided the warning took place. If it did not, due to Poor Communication Kills, Not Now, Kiddo, or the warning not reaching its intended recipient, but the Stock Phrase is dropped anyway, the trope has been inverted, not played straight.

Generally—though not always -- Played for Drama if played straight. If Played for Laughs, expect The Cassandra to be an exaggeratively smug or jerkish in using this trope (a likely consistent trait that lent to no one listening to them in the first place) and at least one indignant victim to try and silence them (usually by yelling a bitter "Oh Shut Up!").

Subverted Trope, The Cassandra has every opportunity to say I Warned You, but doesn't even bat an eye.

Contrast Poor Communication Kills, Not Now, Kiddo, where the information doesn't reach its intended destination. Compare Cassandra Truth.

Comic Books
"Lucius: But I warned ya! I told ya you were bein' played for a buncha saps, but ya didn't listen to me, did ja? Huh? Did ja? that's right! An' when Gran'ma Ben won that race, I was the only one who bet on her! Me an' Gran'ma coulda split that pot, but noooooo... We felt sorry for ya! All bets were off an' we let ya have yer livestock back! All told, I'd say you girls got off easy!"
 * In Bone, Lucius warns the regulars at his tavern not to be taken in by Phoney Bone's Mystery Cow scam. They don't listen to him (or rather, they do, but Phoney tricks them all over again), so after the race ends and the con is exposed, the townsfolk want to lynch Phoney, but are held off by Lucius, who later points out that they have no-one else to blame but themselves for being swindled;


 * In their college years, Reed Richards warned Victor von Doom that he made a few miscalculations that would cause his new invention to malfunction. Victor didn't listen and the machine blew up in his face. Literally. Victor's oh-so-reasonable response was to drop out of college, build a suit of Powered Armor, take over a country, and spend the rest of his life trying to ruin the lives of Reed Richards and his loved ones.

Fan Works
"Mayuri: DO YOU KNOW HOW MUCH THAT COST? Ishida: I told you so."
 * In the Bleach fic Hogyoku Ex Machina, when Ishida warns Mayuri (not very hard, mind you) that it wouldn't be a good idea to have Ichigo attempt to place his reiatsu into a rare and valuable crystal because he's clumsy, Mayuri blows him off. Then Ichigo (having a massive amount of reiatsu and no control over it, hence “clumsy”) makes the crystal explode.

Films -- Live-Action
"Eli: Touch me with that hand again and you're not getting it back."
 * The Book of Eli: In the first fifteen minutes of the movie, when the raider shoves Eli.

"Bruce: We all know how much you like to say "I told you so." Alfred: On that day, Master Wayne, even I won't want to. Probably."
 * The Dark Knight Saga
 * Lampshaded with:

"Bruce: Today you get to say "I told you so." Alfred: Today I don't want to. (they start to walk out) But I did bloody tell you."
 * And its Ironic Echo...

"Venkman: If you shut that thing off, we won't be held responsible. Peck: On the contrary, you will be held completely responsible. (to Con Ed worker) Shut it off. Venkman: Don't shut it off. I'm warning you. Con-Ed Man: I never seen anything like this before. I don't know... Peck: I'm not interested in your opinion. Just shut it off. (later, at the Mayor's office) Stantz: Everything was fine with the system, until the power grid was shut off by dickless here."
 * Ghostbusters: Walter Peck orders a Con Edison worker to shut off power to the Ecto-containment grid despite warnings from Egon Spengler, Peter Venkman, and the Con Ed worker.

"Grandfather: With Mogwai, comes much responsibility. I cannot sell him at any price."
 * Gremlins


 * Randall Peltzer acquires a mogwai anyway. Warnings about them are ignored and the gremlins run wild.

"Grandfather: I warned you. With mogwai comes much responsibility. But you didn't listen."


 * Ironically, the warnings were heeded. The mistake came from trusting an analog clock that turned out to be stopped because the evil Mogwai (later Gremlin) Spike had sabotaged it. The "do not get them wet" rule being broken was an accident.

"K: I warned him. You warned him."
 * Men in Black: After K shoots Jeebs:

"Tim: I warned you! I warned you, but did you listen to me? Oh no, you knew it all, didn't you? Oh, it's just a harmless little bunny, isn't it?"
 * Monty Python and the Holy Grail: Tim the Enchanter warns King Arthur about the deadly Rabbit of Caerbannog but Arthur doesn't believe him. During the battle three of Arthur's knights are killed by the Rabbit, including one who has his throat ripped out.

"Chunk: See, you guys! You never listen to me! I said there was gonna be trouble, but you didn't listen to me! You guys are crazy! You know, you guys are self-destructive! There's a funny farm that has your names written all over it!"
 * The Goonies: After realizing they're dealing with the wanted Fratelli gang.


 * I Robot has "Somehow, 'I told you so' doesn't quite say it." when the robots start rebelling. Or words to that effect.
 * In the first of The Mummy Trilogy remake when the Americans find Imhotep's tomb and one of them reads the warning etched on it. Their guide (and Dirty Coward) Beni runs off yelling to beware the curse. They don't believe him thinking he's being superstitious. Of course Imhotep gets loose and starts draining the life of those that opened the casket. One of the Americans manages to escape but with his eyes and tongue taken. As the surviving American rests at a hotel, Beni (now working for Imhotep) tricks said American into meeting with a healer who is really Imhotep in disguise. Before the American is drained, Beni tells him that he did warn them not to open the tomb.

Literature

 * In Codex Alera, thanks to being Mindlink Mates, Tavi and Kitai preempt the other saying this because they can feel the smug amusement on multiple occasions.
 * Twice, pretty much word for word, in Darkness Visible. The second time is a callback to the first.


 * Polly to Digory in The Magician's Nephew after he falls for the Shmuck Bait that wakes up the White Witch. In Prince Caspian, when it turns out that Lucy was right about the route the group should have taken and they'll have to go back the way they came, Peter congratulates her on pointing this out without saying "I told you so."
 * Rayford Steele, near the end of Glorious Appearing in the Left Behind book series, tells his wife Irene, who has been warning him about Jesus' Second Coming and the Rapture, that she is entitled to "one cosmic I-told-you-so".

Live-Action TV
"Delenn: (addressing the Grey Council) Three years. For three years I warned you this day was coming, but you would not listen. Pride, you said, presumption. And now the Shadows are on the move. The Centauri and the younger worlds are at war, the Narns have fallen, even the Humans are fighting one another."
 * Babylon 5, episode "Severed Dreams":

"Mickey Smith: You see, what's impressive is we met her nearly an hour ago and I still haven't said "I told you so" yet. Rose Tyler: I'm not listening to this. Mickey Smith: Though I have prepared a little "I was right" dance which I can show you later."
 * Doctor Who
 * From the episode "School Reunion":

"The Doctor: I warned you. You did this."
 * The Doctor also plays this line for drama all the time. Especially Ten. It goes with his 'I'm giving you a chance' mantra, which the Monster of the Week almost invariably ignores.
 * He says it verbatim in "Runaway Bride" after blowing up and drowning the last of the Racnoss.


 * In Coach Hayden go to say this over and over after his wiser wife Christine finally makes a mistake and gets arrested after a rowdy bachelorette party by not listening to him.
 * In the Stargate SG-1 episode "2010", Jack O'Neill is very much in "I told you so" mode from the beginning; if they had listened to his warnings about the Aschen ten years ago, they wouldn't need to Set Right What Once Went Wrong now by using the Stargate as a time machine.

Puppet Shows

 * The Muppet Show: Statler and Waldorf says this to Waldorf after using the Evil Eye on him.

Theater

 * In the musical Woman of the Year, two characters sing a song about how great it is to be able to say "I Told You So."

Video Games

 * In L.A. Noire,.


 * Heavy Rain would have this case when.


 * In Assassin's Creed Brotherhood, Claudia's Jerk Ass (former) boyfriend Ducio (who Ezio beat the crap out of for abusing her) makes a return as a ship captain that got his hands on 3 of Da Vinci's paintings that Ezio needs. Ducio, who has no idea that Ezio has become a master Assassin, begins mouthing off, thinking that his crew will back him up. Ezio drops a rather ominous "I am warning you", and Ducio, not taking the hint, begins trashing Claudia. Ezio decks Ducio with a punch to the face and proceeds to mop the floor with him and his crew. Much fun is had for the player.

Web Comics
"Julie: If you had ranks in Knowledge: Arcana, you would've known that would happen."
 * Sweet Bro and Hella Jeff: "I warned you about stairs bro!!!! I told you dog!"
 * In Impure Blood, after the fight. All the more annoying in that his warning had consisted of Vagueness Is Coming.
 * Defied in a strip of Dumbing of Age.
 * Our Little Adventure has a lovely example from Julie to Angelika.

"Elan: Fight, fight, fight, fight the urge to say, "I told you so!""
 * The Order of the Stick, "Nuthin' but Net": Elan, Durkon and Daigo are caught in a trap left by island orcs. Durkon and Daigo get out and try to leave, despite Elan begging them to return under the net... Cue the orcs immediately catching Durkon and Daigo and beating them up.

Web Original

 * On This Very Wiki, the You Have Been Warned page (which is more of a Cassandra Truth), or pot-holing text to Shmuck Bait.

Western Animation
"Azmuth: Ben Tennyson, I warned you of the consequences of tampering with the Omnitrix. Ben Tennyson: I was just trying to... Azmuth: Defy my instructions. Well, you have succeeded! The escape geno types... Ben Tennyson: What? Azmuth: Your transformations. They will perish if they aren't restored to the Omnitrix in 24 hours. And if they do, their powers will be lost to you forever!"
 * In Ben 10, one episode starts with Gwen warning Ben against playing around with the Omnitrix when he doesn't understand it. After accidentally breaking off a part and trying to fix it with gum, it starts changing him into counterproductive alien hybrids. In a Running Gag, Gwen refuses to make the expected "I told you so" speech, which drives Ben crazy waiting for it.
 * Ben 10 Alien Force episode "Vengeance of Vilgax: Part 2"

"Sparks: (closing door) It's not broken, you just... (the door fails to open) Sparks: You just press the... you ju... The door's broken. Wha-wha-wha-what the hell? Marco: Idiota! Cabeza de piedras!"
 * Sealab 2021
 * A Running Gag in the episode "In the Closet", in which Murphy sucker-punches everyone who enters the utility closet they're locked in, declaring "I warned him," when the closest he comes to a warning is "stop it," and then only half the time.
 * In the same episode, however, the trope is played straight when Marco warns Sparks that the door is broken.

"Skinner: Oh oh. Two independent thought alarms in one day. The students are overstimulated. Willie! Remove all the colored chalk from the classrooms. Willie: I warned ye! Didn't I warn ye?! That colored chalk was forged by Lucifer himself!"
 * The Simpsons: "Lisa the Vegetarian," after Lisa has twice questioned the use of meat and her teacher/Lunchlady pressed the "Independent thought alarm."


 * In American Dad, . This episode is even titled "Four Little Words". He realized, though, that he could circumvent this by admitting his guilt before Francine has a chance to say it. It doesn't make her any less enraged, though.
 * Psycho, the minion Seers of Dr. Killemoff in Toxic Crusaders usually says this after his Cassandra Truth gets blown off by Killemoff as ridiculous and the good guys win.
 * In Wakfu season 2 episode 5, Sadlygrove tries to warn Yugo, Amalia and Evangelyne of the dangers of the Dragon-Pig's lair, as he's the only one with experience in Dungeon Crawling. They pay him no heed, used to ignore the Idiot Hero... until the three are struck with a Baleful Polymorph. Grovy then admonishes them with the page quote.
 * Brainy Smurf manages to get in a few of these in some episodes of The Smurfs when he chides his fellow Smurfs about certain actions they failed to take that end up in disaster for the village.
 * Codename: Kids Next Door: In the first of many confrontations, Numbuh five has a candy stolen by her former candy hunting partner now rival, Heinrich. And tracks him to a temple where he wishes to use said candy in a ritual to become the king of sweets (its an odd series). Before he does, he disregards the hieroglyphs in which Numbuh 5 enters and warns him that if he is greedy the candy will taste like asparagus. Heinrich doesn't believe her and proceeds with the ritual. Once its done of course, the curse mentioned takes effect and he blames her. She retorts she did warn him.
 * Phineas and Ferb: Doofenshmirtz was once about to lose his home for not paying the mortgage. When Agent P suggested him to ask his ex-wife for money, he refused to avoid the trope. She warned him not to spend money on the gargoyle statues.

Real Life

 * "One of the few things in life more satisfying than saying 'I Told You So' is being told not to say it."