The Hero / Sidekick dynamic is a very interesting one, with a lot of parallels between that of the hero and The Lancer. Usually, the Hero is older and calmer, while also being a stronger and better combatant than their Hot-Blooded young charge. For these or other reasons, the hero will instruct the sidekick to hang back and observe events, or leave a particularly dangerous fight to him alone.
They never do.
The Reckless Sidekick will rush in headlong regardless of the danger and get captured or otherwise get himself into serious trouble, forcing the hero to choose whether to stop the bad guys or risk rescuing the sidekick. Even if the sidekick manages to mop the floor with the mooks, the hero will gruffly explain he wanted to wait to discover who their buyer/supplier was, and now they'll never find out. On the positive side, if they trail an overly self-reliant or self-sacrificing hero they may well rescue them when they're caught or in danger (though he might not be very grateful). Some shows like to mess with viewers by having them get captured even if they stay put — sometimes you just can't win.
Expect the hero to be justifiably infuriated by this behaviour. The reasons run the gamut of insubordination, recklessly endangering himself and others, and just plain stupidity, though occasionally there are ulterior motives. The sidekick will counter that they aren't a kid (well, a helpless one anyway) and can handle it, or that the hero is overcautious and always has to do things "his way". Expect the sidekick (and hero) to learn An Aesop about how trusting others doesn't just mean blind obedience, but also giving them responsibility and listening to them.
- This was part of the reason a part of the Batman fandom wanted Jason Todd, the second Robin, dead as a doornail. The guy would just jump in at the most inopportune times and mess up Batman's plans, and then he'd whine to Batman that he was being soft. Though the degree to which he showed this trope swung wildly over the course of his career as Robin, depending on the title he was appearing in, and also on how far into the run you look — he got a lot worse at this as time went on in a lot of people's eyes.
- The new Robin, Damian Wayne, is also like this. Being the son of Bruce Wayne and the grandson of Ra's Al Ghul, and being brought up by the League of Assassins, he has a little bit of a superiority complex. It's pretty obvious what character arc they have in mind for Damian as he grows up.note
- Intentionally inverted in the Batman storyline A Lonely Place of Dying:
- Batman, who has sworn to no longer take in a sidekick after the death of Jason Todd, has started becoming brash and impulsive without "someone to look after." Standing right outside a building he is about to investigate, Nightwing, the original Robin now all grown up, shows up to assist him. When Nightwing asks for a plan, Batman shrugs him off and jumps right into the building, walking right into a trap.
- Tim Drake chose to become Robin precisely because he believed Batman needed a sidekick to keep him on the right path.
- Rocket from Icon, whose tendency to rush into situations and shake things up went hand-in-hand with a tendency to save the day. Unlike other examples, she was shown as justified most of the time.
Rocket: This isn't a "sit tight and hope things come out right" situation this is a "do anything and hope it's not wrong" situation!
- The appropriately named "Scrappy Lad" from Ink Pen.
- Both versions were lampshaded in Last Action Hero. Jack: "You ever see those movies where the hero tells his sidekick to stay in the car and he disobeys and gets killed?" Danny: "Good point. <...> Wait, what if staying in the car is what gets me killed?"
- Theres a bit of this in Star Wars: Attack of the Clones. Anakin acts as Obi-Wan's sidekick, and when they face off against Darth Tyrannus, Obi-Wan tells Anakin to stand back and to take him together. Of course, Anakin flips his shit, charges forward and gets tossed aside, leaving Obi-Wan to fight alone and ultimately lose. In the next movie, during the rematch they do take him together, however.
- Dick Grayson acted like a Reckless Sidekick in Batman & Robin. The first major action sequence was a classic example of such, as Dick's insistence in going after Mr. Freeze led to him getting frozen and Batman having to choose between going after Freeze or thawing Robin. Dick receives an ass-chewing from Bruce afterward, and the conflict between the two continues for the good part of the movie.
- Amazingly, Dick manages to be reckless even when he takes Batman's advice and is cautious. When he confronts Poison Ivy in her lair, he tricks her into telling him her plan by pretending to still be in love with her, and survives her kiss by wearing rubber lips. But, once Ivy taunts Robin over this, he removes his rubber lips to one-up her and show he stole a kiss from her, instead of keeping them for protection and tackling Ivy when she doesn't expect it. Ivy becomes enraged and shoves him into her pond, where he is almost drowned by her vines.
- Chuck from Chuck, as he's not a real spy while the other two are trained spies. He's not usually particularly reckless though, and he generally tries to run away from danger unless it threatens someone he cares about.
- Wendy Watson, sidekick Middleman-In-Training in The Middleman starts out with serious concerns about becoming Robin, the Boy Hostage. Early in the series, she does end up as the hostage of a gun-totting psychologist alien-hunter and a gorilla army wielding government scientist, but she ends up saving The Middleman from a troop of evil Mexican wrestlers (before her training with Sensi Ping) and a melt ray soon enough to at least avoid the trope's more negative connotations.
- Gabrielle of Xena: Warrior Princess, especially in the earlier seasons of epitomized this trope.
- The companions in Doctor Who are often like this. In one spin-off novel the Tenth Doctor speculates that he has a sign on his head saying "Ignore this man and any sensible thing he tells you".
Ninth Doctor: (to a stray cat after Rose wanders off) One day, just one day, maybe, I'm going to meet somebody who gets the whole "don't wander off" thing.
- Canonically, the Eleventh Doctor asked "Do I just have a face that nobody listens to?" in ''The Eleventh Hour" when new Companion Amy Pond walked into a room that Eleven knew was dangerous and warned her away from.
- In the backstory of Kamen Rider Double, protagonist Shotaro was this to his boss Sokichi Narumi. Which resulted in Sokichi's death.
- Richie in Highlander. He did improve a little in the later seasons, before he got axed, but early on, he was always getting himself into trouble-or sometimes getting Duncan in trouble.
- Blair, sometimes, in The Sentinel.
- Ace Lightning has the stereotypically fiery red-headed Sparx.
- Lewa for the first few years of the BIONICLE storyline. He's supposedly become less reckless and impulsive over time, but he's still the one who usually ends up in trouble and needs rescuing.
- Freedom Force devotes a couple missions to one of these. A fanboy of the game's Captain America Expy, he gets shot instead of him by a machinegun-toting baddie and is saved only by an emergency blood transfusion from his hero. The transfusion gives him superpowers of his own, so he goes off on his own to find the villains' hideout (against orders to remain in safety and recover), and nearly gets himself killed again before he gets saved by another hero.
- Chie and Naoto show signs of this in Persona 4 before they get their personas. Chie rushes right into a shadow infested castle to find Yukiko, ignoring the advice of the two guys who have been here before, have a better understanding of the danger at hand, and have the means to fight it. Naoto, on the other hand, was a tad smarter but still very reckless. Her idea was to make herself the next major target for the serial killer. All of the members of the gang were almost entirely past victims who lived, so the plan was to find the truth herself and let the gang save her, since she knew enough that they had been doing so for awhile. However, she had no concrete facts and was only lucky that her theory was in the right ballpark. Even then, it didn't prepare her for meeting her inner shadow...
- He's by no means a sidekick, but ex-00 Agent Jack Hunter from Goldeneye Rogue Agent is heavily implied to have been this. It's what gets him dismissed from MI-6 and hired by Goldfinger.
- Gordito in The Adventures of Dr. McNinja tends to act this way, though he also shows signs of being very thoughtful and clever. For example, after catching "Plumber" Victor trying to install cameras in the Doctor's office, he sets off on trying to get rid of him... by hiring another plumber and firing Victor.
- The Non-Adventures of Wonderella: Wonderita tends to get like this, simply because she's The Ditz and doesn't necessarily realize she's in a dangerous situation.
- From "The Things I Will Do if I Am Ever the Hero"
I will not make the sidekick wait somewhere while I go on ahead. He'll only get into worse trouble than he otherwise would.
- From "The Things I Will Do if I Am Ever the Sidekick":
If the hero tells me to stay put while he goes on ahead, I will do so instead of sneaking around and getting captured.
- In the Global Guardians PBEM Universe Barnstormer's sidekick, the young Tailgunner.
- Quinn from Demo Reel. He's more of a partner to Karl than a sidekick, but he's still younger, more passionate and Karl looks after him when he's sick.
- Godzooky in The Godzilla Power Hour had the habit of flying around Godzilla's head and trying to fight the evil Monster of the Week WHILE Godzilla himself was trying to stop said evil monster.
- Jade in Jackie Chan Adventures. While she does prove invaluable, an in most cases her quick thinking is what saves the day, her insistence on ignoring any order of Jackie's, no matter how sensible and life extending, makes her an avid Idiot Ball juggler.
Uncle: (after Jackie tells Jade to do nothing) Jade never "does nothing".
Jackie: I know, but I feel like I have to say that.
- Scooby-Doo: Scrappy Doo. Considering all of the monsters of the week were old men in costumes, Scrappy might have been able to take them.
- Subverted in Batman: The Brave and the Bold; Robin is now a solo hero in his own right, but Batman still expects him to hold back and fight the Mooks. So it's quite justified for him to object to this.
- Zack in the 1987 Teenage Mutant Ninja Turtles wants so badly to be a Turtle that he was the source of much of the conflict in his first appearance. His second one gave him some restraint, but not much.
- Penny from Inspector Gadget averts this. She is the competent one and the main hero is Inspector Oblivious.
- My Little Pony: Friendship Is Magic:
- Rainbow Dash tends to fill this role compared to the rest of the Mane Six, especially in the first season.
- This trope is inverted in the episode "Wonderbolt Academy", where Lightning Dust is a reckless leader and Rainbow Dash is her more sensible wingpony.
- While not an official sidekick, Max Gibson fills this role on occasion for Terry's Batman in Batman Beyond. Used most egregiously in the episode "Final Cut", where her recklessness almost gets her killed by an assassin.
- Miko Mai of Transformers Prime, quite infamously, is always hankering to charging off into action, especially if that means combat, alongside her friends and has directly endangered them at least half a dozen times as a result of this. The kicker? Miko is a 15-16 year old Japanese schoolgirl. Her friends — and their enemies — are giant alien robot killing machines, all of which are armed to the teeth, covered in armor that resists most conventional Earth firearms, nevermind the improvised weapons Miko tries to use, and big enough that they could easily squish her underfoot like a bug. Despite this, Miko just never seems to learn that she has no place in the actual combat. Though she does holds her own in season three with the help of the Apex Armor.