[[caption-width-right:350:Icons for several characters from the roleplay. ([[LoadsAndLoadsOfCharacters This isn't even close to being everyone.]]) [[labelnote:Top to bottom, left to right]] Nanatsuki-no-Hanabira, Natsuko, Pat Thropp, Jim, *Lunar, Prince Prism, Princess Morningstar, Ryou Shion, Rook Naberrie, and Heather Mouse-Cricket.[[/labelnote]]]]

Have you ever messed with one of those silly 12-character memes and gotten a "what if character X got character Y pregnant?" question, and then wondered what would have happened if that child was actually born?

The intrepid weirdos of a certain Website/FanFictionDotNet forum did. And this is the RP (found [[https://www.fanfiction.net/forum/Deadly-Mistakes-or-We-Came-We-Saw-We-Mostly-Cried-A-Lot/130820/ here]]) they created based on that idea.

Then a few members of that group of intrepid weirdos turned out to be jerks and Gamergaters, so then a big bad SJW stole the RP along with all the decent members.

And then the group made a [[http://deadly-mistakes.wikia.com/wiki/The_New_and_Improved_Deadly_Mistakes_Wikia Wiki]]!

Now has its own [[ShoutOut/DeadlyMistakes Shout Out page]].

!!''Deadly Mistakes'' includes examples of:
* BadassFamily: Since nearly all of the characters are crossover kids, there are a lot of these.
** WorldOfBadass
* BeautyBrainsAndBrawn: Can apply to several trios in the main cast.
** Kainashi, Yuuka (perhaps interchangeably with each other) and Nan respectively.
** Inochitori, Rowan and Jasper.
** Eve Halle, The Professor and Serena.
* BigBadDuumvirate: The Master II and The Blue Hood teaming up in the second arc.
* BonusBoss: [[spoiler: At the motel, the Snow King was going to be this to The Professor if The Professor did not tread carefully enough with him beforehand.]]
* BreakThemByTalking: What the Mistakes have to do with most Fetters.
* BreakingTheFourthWall: Yuuka did this subtly in Chester's lab by acknowledging the roleplayer of the upcoming BigBad.
* BreatherEpisode:
** The Mistakes' lunch outing at the combination Chinese-And-Japanese restaurant. Of course, shortly after they ran into Eve Halle, but...
** Meeting Chester, Swallow, Jewel and Princess Candy at Chester's lab after pacifying the Snow King.
* CallBack: The plan to perform sentry duty at the motel is a call back to when the Mistakes kept watch in shift at Thaddeus' house back in the original timeline.
* CharacterDevelopment: Happens for most if not all of the Mistakes, but especially the ones with Fetters.
* CharacterMagneticTeam
* FourPhilosophyEnsemble
** The Cynic: Kainashi, Canaria, Alvan, [WIP]
** The Optimist: Wren, Ayame, Prism, Jacqueline [WIP]
** The Realist: Yuuka, Nan, Belial, Claude, Ryou [WIP]
** The Apathetic: Demasiado [[spoiler: seemingly]], Corinne, [WIP]
* FourTemperamentEnsemble
** Sanguine: Yuuka, Demasiado, Ayame, Prism, Heather, Jacqueline, [WIP]
** Melancholic: Nan, Canaria, Isaac, [WIP]
** Phlegmatic: Wren, Belial, Ryou [WIP]
** Choleric: Kainashi, Claude, Corinne, Grammaire[WIP]
* EnemyWithout: The Fetters.
* HitchhikerHeroes
* LoadsAndLoadsOfCharacters
* MadScientistLaboratory: Chester and Jewel have at least one.
* ThePsychoRangers: Actually did appear canonically, as minions of The Master II.
* RagtagBunchOfMisfits
* ThoseTwoBadGuys: The Master II and Nan used to be this in the first arc.
* WireDilemma: Happened when Rowan, Yuuka and Isaac had to deactivate The Master II's Genesis Bomb.