The villain wants/needs the hero to go though a process that will benefit him and kill the hero. If the hero is killed some other way, then that benefit is lost. The villain may not even care at all about the hero, but about said benefit. For example, what a vampire really wants is the blood of his victims; he won't get anything if he vaporizes people with some futuristic giant laser gun.
Freeza shows that he completely outclasses Goku and the rest of the heroes while only fighting at 50% power and that he could kill all of them in an instant, and yet he toys with them and lets the fight drag on... until Goku transforms, that is.
During the Cell Saga, Vegeta, after having training for a year in the Room of Spirit and Time, becomes an Ascended Super Saiyan, and much, much stronger than his opponent, Semi-Perfect Cell. Rather than finish him here, Vegeta lets Cell absorb Android 18 and upgrade to his Perfect form, lusting for a greater fight. Cue Perfect Cell completely Curb-Stomping Vegeta, and later Trunks. While Vegeta is on the good guys' side at this time, the effect is the same.
Cell himself makes the exact same mistake. After ascending to his Perfect form, and defeating Piccolo, Vegeta, Trunks, and Android 16 in the process, he becomes the most powerful being on earth. Rather than kill everyone he opts to give the Z-Fighters 10 days to prepare for a tournament.
Those were probably the Vegeta cells inside him, as Vegeta himself does this a few times as well, as mentioned above.
Dragon Ball in General inverts this trope almost as much as it plays it straight. The Heroes are just as prone to holding back in their fights or letting the villains go, just to result in them coming back stronger later. The worst offender is probably Gohan, who has a problem with holding back too much during his fights and giving the villains too many openings.
Done quite deliberately by Jeremiah Gottwald in the Grand Finale of Code Geass, when he calls off Lelouch's Knightmare Royal Guard and duels the attacking Zero/Suzaku by himself, so as to allow Suzaku to convincingly kill Lelouch for world peace.
In episode 4, Jeremiah does this NOT on purpose whenClovis' personal car—hijacked by Zero and company—make their way towards Suzaku's execution. When asked by his subordinates in security if they should blow up the car, Jeremiah replies "No! I shall take them myself!" If it hadn't been for Jeremiah's arrogance, the whole show would've ended right then and there.
Lelouch himself does this several times, such as when he taunts Euphemia during the hostage situation about his hatred of the royal family (planting the seeds in her mind that Zero might be Lelouch). He also reveals to Suzaku that he knows Suzaku's deepest secret—that Suzaku killed his own father—in order to appear omniscient. Not only does this fail to recruit him,but Suzaku begins to suspect Zero's identity as Lelouch is one of the few who knows Suzaku is a patricide.
Subverted in the 5th Kara no Kyoukai movie. Araya mercilessly destroys Tohko but keeps her head alive on purpose - she's created multiple exact duplicates of her own body and linked them to herself, so whenever she is "killed" her consciousness transfers to the next body, making her depend on this trope. When Alba fulfills the trope and crushes her head, she comes back with a vengeance(-in-a-box).
After stompingNegi and his team, Fate decides they aren't completely worthless because they barely pulled off a recovery not dying of the wounds he inflicted. Instead of, you know, killing them in the face like he's clearly capable of, he says 'Okay I'm bored just gonna blow the gate up now. By the way, you suck Negi. Go level grind moar. Later' May be justified in that he intended to use Negi and seems oddly reluctant to actually kill people. Also definitely planning on using Asuna for something, but we don't know what yet.
In the Kämpfer anime, Kaede had one of the good guys under her control, and used her to defeat the other blue and red Kampfers. But instead of just killing them like she said she would do, she tied them up with a chain, gloated at Shizuku, and tried to use the mind-controlled ally to kill them instead. However, not only did said victim break free of the mind control, but the heroes got Heroic Resolve so strong they broke free and went to town on the enemy.
At one point in Sonic the Hedgehog: The Movie, Tails is using a bit of Applied Phlebotinum, about the size of a wrist watch, to mess with Metal Sonic's programming. From off-screen, Dr. Robotnik whips out a laser gun and shoots the machine right off Tails' wrist, then he orders Metal Sonic to kill Sonic and Tails. Fridge Logic dictates that Robotnik could have just as easily saved a step by shooting Tails in the head.
FTA: Why doesn't he just put a bullet through Tails' head?
NTom64: Because it's a family film.
In Fullmetal Alchemist, Lust stabs Mustang and Havoc and leaves them to bleed to death on the floor and doesn't actually watch them die. Cue her surprise when Mustang comes back to kill her, having cauterized his own wound with fire.
Quite prominent in Naruto; every time a villain has the hero in the bag, they invariably will stop to gloat, allow said hero to get back up to make the fight more fun, or just decide to be idiots instead of killing them right then and there.
Notably when Orochimaru had the Third cornered with a kunai and instead of just SLICING HIS HEAD OFF like any smart person decided to do a huge elaborate drama in which he summoned the Third Hokage's own teachers to kill him, resulting in Orochimaru losing the use of his arms.
Unbelievably Subverted with the power of Edo Tensei - everyone under its control is already dead. As such, a Magnificent Bastard may pull any form of Kick the Dog they want without fear of getting killed by retaliation. However, they can still have their souls sealed away or put to rest. Absolute villains like Deidara, Kakuzu and Madara Uchiha push it to extremes, while others, like Sasori, Gaara's father, Nagato and Itachi use it as means to apologize or atone. Itachi even has his free will back!
At one point in Saki, Amae Koromo, who has been dominating the game since she appeared, has the opportunity to give one of her opponents a negative score, thus instantly ending the game and winning the tournament for her team. However, instead of doing this, she quite deliberately makes a lower-scoring move which reduces said opponent's score to exactly zero instead (according to the rules of this particular tournament, someone with a score of zero has a chance to come back) just because she wants to psychologically manipulate everyone and prevent the other players from making a certain type of high-scoring move. Sure enough, this buys our hero just enough time to come up with a way to win.
In the second Black JackOAV, when the title character stumbles upon an international drug ring working with a local hospital administrator in the course of treating a coma patient, instead of just shooting him, the gangsters drug Black Jack and leave him to die in a burning peyote grow op.
Sailor Moon has Queen Beryl put Jedite in Eternal Sleep just as he's about to reveal who the Sailor Senshi really were. Had she not been so impatient to kill Jedite for his latest failure, the Sailor Senshi would've been goners for sure.
In Haruhi Suzumiya, Ryoko Asakura tries to kill Kyon with a knife, giving him a chance to dodge. When that doesn't work, she freezes him in place, and it is later implied that she could have just outright deleted him from existence. She's a malfunctioning alien bio-robot, so it makes sense.
The Dark Signers from Yu-Gi-Oh! 5Ds weren't known for being smart, but the biggest example of stupidity on their part was when Yusei's duel with Kiryu left the hero battered, wounded, close to death, and with a fear of the villain that would take several episodes to recover from. Why didn't Kiryu finsih him off when he had the chance? He claimed it "wasn't the right time." (Kiryu was almost the living definition of Axe Crazy at the time, so at least he had that as an excuse.)
Luppi thinks he's taken down Hitsugaya in one strike and doesn't follow through. Lampshaded by Hitsugaya when he points out that all it did was give him all the time in the world to set up an attack that could curb-stomp Luppi. Luppi was also mocked by his peers upon returning to Hueco Mundo for having been defeated so completely.
Barragan suffers from this at the end of his fight, despite being untouchable to his opponents. Hacchi realises that if Barragan's power is as dangerous as Barragan claims, then Barragan himself would be vulnerable to it. He uses kidou to expose Barragan to his own power and, sure enough, Barragan quickly dies.
Aizen, who is usually very savvy, manages to get two of his own.
He's so focused on defeating the power of the strongest offensive zanpakutou in Soul Society history that he fails to think of what will happen when it's removed from the picture. He takes out Yamamoto's zanpakutou very quickly, but Yamamoto points out that shinigami aren't helpless without their zanpakutou and proceeds to prove it. Aizen fails to achieve his objective of killing Yamamoto and admits he underestimated the old man.
Aizen sets up an elaborate method of ensuring Ichigo can train for a power upgrade before they fight. He was hoping Ichigo would achieve a level of power strong enough for Aizen to reach a new level of power. Unfortunately for Aizen, he completely underestimated Ichigo's growth potential and ended up being curbstomped.
In the Ultimate Spider-Man series, one villain, Hammerhead, tries to avoid this trope by pulling out a gun and shooting a troublemaker; unfortunately said troublemaker manages to catch the bullet unharmed, much to Hammerhead's surprise.
Lampshaded and cleverly justified in the classic Disney comic story "Mickey Mouse Outwits the Phantom Blot." In the story, the villainous Blot puts Mickey in death traps time and time again, but Mickey always escapes. It turns out that The Blot does this because, despite being evil, he can't stand to actually see anyone get hurt, let alone die. So he constructs elaborate traps to kill Mickey for him, then always leaves because he can't bear to watch.
Taken to extremes in one of the Archie Sonic the Hedgehog comics. Dr. Eggman decides he's sick of fooling around with Sonic and launches an all-out attack on his hometown. His forces manage to blast nearly every single good guy (except three) with powerful lasers that seem to vaporize them on contact. He then beats the crap out of Sonic for good measure. Looks like Eggman has finally won... except that those lasers didn't kill Sonic's friends, they were just teleport beams, which sent them all to cells at Eggman's HQ. Eggman announces he'll kill them all THERE... even though he could have killed them much more easily by simply making his lasers lethal in the first place.
This is doubly stupid because Sonic believes everyone is dead... until Eggman TELLS Sonic that his friends are alive, and where to find them. Then he's actually surprised when Sonic mounts a rescue and frees them all. If he'd just kept his trap shut, Eggman would have had plenty of time to kill everybody.
Averted in Black Orchid half the tropes on that page are related to that single moment.
The Yellow Bastard in Sin City was fine leaving Hartigan hanging by his neck and didn't stick around long to make sure he couldn't escape, which he did. To his credit, people typically die when they are hanged.
Hanged people mostly die from breaking their necks. If one survives the fall, failing to suffocate is not common but very much possible. So it's more like a case of generic stupidity owing to lack of research on the subject than the Bond Villain kind.
Despite being a supergenius, Doctor Doom falls prey to this a lot whenever he's trying to kill his hated Arch-Enemy Reed Richards of the Fantastic Four. This is sort of justified though, because Doom's end goal isn't killing Reed — it's proving to Reed that Doom is smarter than him, and then killing him. Therefore, killing Reed without gloating about how he has been outsmarted and making him watch Doom Take Over the World and kill everyone Reed loves isn't just a tad disappointing to Doom — it would be completely antithetical to Doom's entire purpose in being evil.
In Dracula Vs King Arthur, Dracula has Arthur captured and brought to Dracula where he could've easily killed him and took over the kingdom. But rather then doing the sensible thing to clinch victory, he instead decides to "break his will" and just have Arthur throw into the ocean after his subjects and he feed on him. As you can imagine not only does this not happen, but Arthur recovers, gains some new weapons from the Lady of the Lake and regroups his remaining forces for a final battle which ended in Dracula's defeat. Yeah, nice one, lord of the darkness.
The Phantom wouldn't have lasted for one generation, let alone the twenty-one he's currently at, without practically every enemy he's ever met falling for this trope. Phantoms do get occasionally killed in the line of duty, but it's usually in open combat and not because someone's clever enough to Just Shoot Him when they have him captured.
Though the fact that he's up to 22 Phantoms suggest some of his enemies can bring themselves to Just Shoot Him.
Played straight later with Lung, Jade's bodyguard kills him for torturing her.
In With Strings Attached, the Big Bad (Brox) asks The Dragon (Grunnel) why he wouldn't let her kill George and Ringo, who were both useless to them. Grunnel responds with a number of reasons, including that it's funnier to have them powerless and unable to stop the proceedings. (Also, he does genuinely like them.) Later, after it becomes clear that the two have managed to get useful stuff done despite having their magic neutralized, Grunnel apologizes to Brox for being wrong. The latter isn't terribly upset, though, as she believes that they still can't bull their way through dozens of wizards to get into the warehouse.
Diamonds Cut is a Bond fan film, so its presence is guaranteed.
In Clear Skies 3, Ghost wastes time monologuing, which gives Charlie and Sol time to salvage a shell and use it to kill him.
In the Facing The Future Series, Technus managed to keep Danny, Sam, and Tucker busy while he downloaded himself into the cybertron satellite again, however, he failed to focus on Valerie and Skulker who rerouted his link to Tucker's PDA.
After a dinner goes wrong, Dr. No just orders his guards to beat up Bond and get him imprisoned. 007 later escapes, nearly getting drowned in the process (however, being the first Bond film nobody knew how dangerous he could be).
In the book, he also had Bond run through Dr. No's death course. Bond was close to dying through it, multiple times.
As did everyone else Dr. No had "tested"; the course was designed to kill. The only difference Dr. No ever expected was how long it would take. Funny how much difference a stolen lighter and a steak knife (and Bond!) can make...
Professor R.J. Dent has his moment when he empties his entire magazine on a dummy Bond had put on his bed just before Bond himself intercepts him from behind the open door instead of just shooting once, making sure the "body" wasn't moving, and being done with it. "You've had your six", indeed.
In fairness to Dent, if he hadn't emptied fired all his six Bond wouldn't have taken his eyes off him after ordering him to drop the weapon. Once he fell for the dummy Bond he was toast.
Averted by Goldfinger, who keeps Bond alive because if he dies, then the Secret Service will just send in some guy called 008. Goldfinger instead tricks Bond's superiors into thinking that the situation is well in hand. Also justified in the same film - Goldfinger originally was going to have Bond sliced in half by a laser. The inversion is that this was going to work; Bond had to talk his way out of it, and was seconds away from losing his manhood when Goldfinger agreed.
Yet Goldfinger displays incredible stupidity (or maybe just bad writing) in dealing with his gangster accomplices. While he is showing them his plan with a miniature Fort Knox, one demands to leave and take his gold with him. They load the gold in a car and Oddjob drives him away, ostensibly to the airport. Then Oddjob kills him but instead of just dumping the body he takes the car, with the body in it, to an auto yard where it is cubed, along with the gold. He then returns to the farm where Goldfinger says they will have to extract the gold from the car and remains. This would be all too complicated and stupid as it is. However, after that gangster left, Goldfinger had the room sealed and all the other gangsters gassed to death. So why not just excuse himself for a minute, leaving that one guy with the others and kill them all at once, instead of destroying a car for no reason?
Justified in On Her Majestys Secret Service, where just for once the villain genuinely has an actual sensible reason for keeping the captured James Bond alive and explaining the plot to him: Bond is trusted by the authorities and familiar with Blofeld's record, so his report will help convince the UN that the threat is serious.
In Diamonds Are Forever, Mr. Wint and Mr. Kidd had Bond unconscious and they simply dumped him in an unfinished pipeline and left, assuming he'd eventually die. Doubly stupid, as this was the second time the pair had been given an unconscious James Bond to dispose of; the first time they tried to burn him alive, and it didn't work then; Shady Tree and Morton Slumber get him out of the retort when Tree discovers that Peter Franks' remains had been stuffed with fake diamonds planted by Bond and the CIA before being transported to Slumber, Inc. to be burned, and Bond takes the opportunity to just waltz out of Slumber, Inc. when Tree tries to question him about the whereabouts of the real diamonds.
Bond takes up Hai Fat's invitation to join him for dinner in his mansion while pretending to be Scaramanga, not knowing that the real Scaramanga had already gotten in touch with the guy. When he arrives there late at night, he's incapacitated by some guards in an ambush. As they're about to kill him, Hai Fat forbids them from doing so because he doesn't want Bond killed in his home. They'll just take him somewhere else to finish him off right? Nope. Hai Fat has Bond placed in a karate school to... get beaten up? Maybe?
Justifiably invoked by Scaramanga late in the film; he freely admits that he could have used his solar-powered laser to blow up Bond's plane before he even landed on the island, but chose not to do so because of how unsatisfying it would be. (Scaramanga previously got angry at Fat for the previous incident and killed him.)
In the teaser of For Your Eyes Only, "Blofeld" opts to zig and zag Bond around in the helicopter, instead of just crashing it as soon as he takes control.
The worst example is probably GoldenEye, when the villains have several opportunities (most notably in the Statue yard) to just shoot Bond and don't. Then Ouroumov has the chance to shoot Bond, announces that he is about to do it, and then is promptly cold-cocked. What moves this into beyond-belief territory is that both have direct evidence of how dangerous he is when cornered.
In the Statue yard, they were trying to frame Bond and Natalya for the theft of the helicopter. If a post-explosion examination of the bodies revealed that they had been shot beforehand, it would have raised suspicion.
Wholly averted by the Big Bad of the film. Given Janus's identity and motivations, it's not merely enough to kill Bond, and if it would be he usually has more pragmatic reasons for keeping them alive. The aforementioned frame up is just the first such example.
Elliot Carver was preparing to do this in Tomorrow Never Dies, leaving Mr. Stamper and his henchmen to torture Bond and Wai Lin for an ungodly amount of hours, but the heroes decide to make their escape before Carver even leaves the room.
It's either Lampshaded or a spectacularly bad example, albeit not involving Bond himself: In Die Another Day, two henchmen have Jinx at their mercy, and one actually proposes shooting her... but the other one wants to do it with lasers, and gets his way, allowing Bond time to arrive and rescue her.
Earlier in the film, Bond gets out a Bullet-Proof Vest and Moon keeps shooting it until it falls off into the ground.
The villain in Skyfall initially toys with Bond instead of killing him because it was part of his plan to get to his real target, M. Later, however, his failure to take advantage of various opportunities to kill the heroes is best chalked up to Plot Armor and Sanity Has Advantages.
To be fair, General Whittaker in The Living Daylights only monologued to distract Bond as a remote control gun was aiming to shoot him.
Films — Other
Justified in the same fashion in True Lies, where Arnold Schwarzenegger's character Harry Tasker is captured alive so that he can document for the authorities that the terrorists are capable of carrying out their threat, and afterward when they intend to torture him since he's an American spy who most likely has some valuable information in his head.
Subverted in the 1997 movie version of Le Bossu. After a long sword fight, the hero gets cornered by some soldiers and the Psycho for Hire. From what we have seen earlier, it will be difficult, but possible for him to escape. At this moment, the villain, exasperated by the long fight, steps up to the Psycho For Hire, draws his gun, asks why they can't do it "quick, modern and effective" and shoots the hero, who only survives because of his Character Shields.
In the film Sherlock Holmes and the Secret Weapon, Professor Moriarty originally intends to kill Holmes off quickly, but Holmes goads him into coming up with something "more creative," giving an example himself of the sort of death trap he would use if he had Moriarty at his mercy. Moriarty decides to prove his superior intelligence and creativity by... using the exact idea that Holmes just came up with! He does at least stick around to watch the death trap in action, and prepares to shoot Holmes when he decides it's taking too long; but he waits a bit longer than he should have, and Watson rescues Holmes Just in Time.
In Tim Burton's Sleepy Hollow, Katrina's stepmother has Katrina unconscious, isolated, and is armed with a pistol. Also, everyone believes the stepmother is dead, so no one would come looking for her later. Rather than just shooting Katrina, she decides to spend a lot of time summoning the Headless Horseman to do the job, giving Katrina plenty of time to wake up and run away (though granted the stepmother is hardly concerned when Katrina escapes, probably as she figures she's dead soon anyway).
Annoyingly present in Terminator Salvation, when after luring John Connor into the heart of its main base, Skynet sends a single unarmed T-800 to dispatch our hero. Yeah. In a base probably full of hundreds of killer robots with guns, Skynet decides to send ONE unarmed unit to kill the hero. And it doesn't bother to send more armed killer robots after the fight drags out, with Connor getting backed up by Cyborg Marcus.
Somewhat justified that the T-800 DID managed to critically wound John and if Marcus hadn't volunteered for a heart transplant, John probably would have died.
Skynet doesn't even seem concerned when the fight spills into the T-800 assembly line, where countless Terminator power cores (I.E. easily set off miniature nuclear devices) lay for the humans to jury rig into a bomb that will destroy the entire base if they manage to defeat that lone T-800 you sent to kill them.
In The Last Dragon, media-obsessed villain Eddie Arkadian first plays this trope straight, stopping a minion from plugging the hero during a big staged fight because it would ruin "the show". But then at the end of the movie when the show is "over", he whips out his own gun, gives a short sneering speech about "all this kung-fu crap", and fires. The hero catches the bullet in his teeth.
In the Tom Selleck Australian Western Quigley Down Under, Quigley has rejected the Big Bad's offer to hire him to kill the local aborigines. The villain (played by Alan Rickman) has his goons beat him into unconsciousness. It would be easy to simply shoot Quigley in the head, bury him in a shallow grave, and tell the British soldiers that he went back to port. But that would mean the movie would only be a half-hour long, so Rickman decides to have his men take him into the middle of the Australian desert and leave him to die of exposure. Inevitably, this backfires spectacularly.
As if that wasn't enough, he captures Quigley AGAIN, decides he's going to beat him in an Old West style quickdraw, and gives the man a fully-loaded pistol. Fortunately, Quigley never much cared for pistols...
In Superman, Luthor has Superman incapacitated by Kryptonite and unable to get out of his swimming pool. Then he leaves him, expecting him to die - even though he just learned that his girlfriend's mother lives in the town that one of his bombs is about to destroy. Somehow, he does not see her betrayal coming.
In a non-lethal example, in the final face-off in 8 Mile, Papa Doc makes the grave, and just plain stupid mistake of letting B. Rabbit go first. Big mistake, as it lets Rabbit take away every single possible verbal weapon Doc might have used against his opponent, thus losing him the battle.
Leroy and Roger in ''Mystery Team." Justified in that the heroes are kids.
In The Wolf of Wall Street, Belfort invites Agent Denham to see him on his yacht, complete with A Lady on Each Arm, and he even boasts of putting on an act as a "bond villain". He then behaves just like one, by offering to bribe Denham and boasting of his Paid Harem while Being Good Sucks. As Belfort's lawyer notes his invitation to Denham to see him in yacht is a really stupid thing to do, since it increased the FBI's focus on him and on the operations that he's trying to hide.
After John's cover is blown in Stone Cold, the bad guys put him into a chopper (which is vital part of their Evil Plan) where they plan to strap him with explosives and then drop him on unsuspecting cops below. He gets loose, some other guy gets blown to bits mid-air instead and the chopper crashes.
Had Bane not choose to end Batman's life in their first confrontation in The Dark Knight Rises, he and Talia al Ghul would have succeeded in their plan to destroy Gotham City. Batman even asks Bane in prison when he first woke up: "Why don't you just kill me?" to which Bane replies, "You don't fear death. You welcome it. Your punishment must be more severe."
Later, Talia monologues at length to Bruce about how much better revenge is when it's done slowly, giving the heroes enough time to block her remote triggering of a nuclear bomb. Bruce lampshades this shortly after, responding, "maybe the slow knife was too slow."
Once Talia leaves Bane, having learned his lesson, ignores her order to let him live and tries to kill him then and there, Catwoman's Big Damn Heroes arrival saves him.
In Wild Wild West, after Loveless captures West and Gordon, he fits their necks with the blade-attracting magnets that the professor in the opening was also killed with. Then he leaves before ensuring their demise.
The villains twice have our heroine helpless in their power in The Long Kiss Goodnight, and fail to just shoot her. The first time is justified by their need to interrogate her in order to learn what she knows of their plans, but despite them knowing how dangerous she is, they leave only one guy to handle her and she easily kills him and escapes. The second time, full on Bond Villain Stupidity kicks in as the bad guys fully describe their evil scheme to her then leave her Locked in a Freezer while they take her partner out and debate whether to shoot or stab him. They don't have time as she manages to blow up the building, having filled her daughter's dolly with gasoline just in case she needed to set stuff on fire.
In Avatar, the humans exhibit this brand of stupidity. The whole point of the plot is how the White Man...oops, human race as such...is willing to kill women and children purely for greed (completely unliketypical hunter-gatherer societies). But...Unobtainium is a rock. Rocks survive saturation bombing. If the humans are so evil, they would just bomb everything around the tree, then scoop up the slightly blackened rocks. The Na'vi would never have a chance to try Rock Beats Laser, they'd be too busy burning and suffocating. A modern military only puts boots on the ground when it's trying to minimize civilian casualties (or at the very least, subdue a population it prefers not to simply kill wholesale).
Older than Television: In John Buchan's 1919 World War One spy thriller Mr. Standfast, the villain, having finally captured the hero Richard Hannay, explains his evil plans at great length. Buchan was arguably the first writer of modern spy thrillers.
The Discworld novels Men at Arms and Witches Abroad both explain that bad guys don't kill the good guys straight away because they want to gloat, and make sure the good guy knows he's been beaten. In the first book it serves to show Carrot as a Good Man because he straightforwardly kills the bad guy without explanation; in the second it gives Granny Weatherwax a Not So Different moment, since she rather likes people she's defeated to know about it as well.
Lampshaded and neatly subverted in Mort. Mort, Princess Keli, the wizard Cutwell and others being surrounded by the villainous Duke, who Cutwell correctly identifies as "not the kind of man who ties you up in a cellar with just enough time for the mice to eat your ropes before the flood-waters rise. This is the kind of man who just kills you here and now." Also played straight in that the Duke is willing to offer them life-long banishment (we know how well that kind of thing turns out).
Unsurprisingly, this happens regularly in the James Bond novels. Some (Mr. Big, who has actually put quite a bit of thought into it) are smarter about it than others (Red Grant, where even Bond notices). However, the highlight has to be The Man with the Golden Gun, when it's actually not Bond, but M who gets this treatment from Russia's newest assassin, James Bond.
In From Russia with Love, the Soviet Chessmaster Kronsteen lays a complicated and near-perfect trap for James Bond. Everything works as planned, all the pawns including Bond go through their predicted moves, and Bond gets exactly where the Soviets wanted him. But at the crucial moment the assassin Red Donovan - an Irishman who hates the English - makes the fatal mistake of engaging in prolonged crowing, boasting and gloating instead of just going ahead with his assigned task of killing Bond. This allows Bond the chance to improvise a desperate last-moment plan which works, enabling him to kill Donovan and use the information which Donovan carelessly revealed in order to catch the senior Soviet operative Rosa Klebb.
This is probably the defining trait of Dr Mabuse, a diabolical mastermind with a few self-destructive tendencies from a series of German novels and films. He has been called the direct forerunner to Blofeld. Observe the Meaningful Name: "m'abuse" is French for "abuse myself". Mabuse is his own worst enemy.
Iceclaw: If Tigerstar can harm cats like he can and walk in their dreams, why doesn't he just do it to Firestar, take revenge, and get it over with?
Vicky: Because Tigerstar wants a long-drawn out kind of vengeance, involving as many cats as possible, so that Firestar truly suffers. ...
Happens in Harry Potter. Since Voldemort likes to establish a sense of grace and grandeur into his actions, he doesn't just kill Harry and be done with it.
Near the end of Harry Potter and the Goblet of Fire, Harry has been disarmed, gagged, and tied securely to a gravestone. Rather than simply killing Harry after using his blood to regain his body, Voldemort not only has Wormtail cut him loose and give him back his wand, but insists on fighting him in a one-to-one duel and forbids interference from any of his Death Eaters, for no other reason than to prove, once and for all, that he is the stronger of the two. The final result of this is that Harry manages to escape and tell the world about his return (not that many people listen at first).
In Harry Potter and the Half-Blood Prince, Draco Malfoy gloats triumphantly when Albus Dumbledore lies in a weakened state completely at his mercy, but fails to kill him despite having been ordered to do so on pain of death as he can't bring himself to do it. This leads to Severus Snape having to step in for Draco and finish off Dumbledore.
Uncharacteristically occurs with Grand Admiral Thrawn, usually one of the more Genre Savvy people in the Star Wars Expanded Universe. He has just betrayed Mara Jade by tricking her into revealing Talon Karrde's location, leading to his arrest by Imperials who will torture him if he doesn't hand over important intel, and then smugly mouths off to her face about it. Mara predictably goes berserk and attempts to attack Thrawn, at first physically then through the Force. Both of these fail, leaving Thrawn with the question of what to do with a still visibly enraged and always emotionally unstable Jade. Instead of killing her, he allows her to live, and lets her out of his sight aboard his ship before letting her go. Jade then predictably hacks into the computer network of Thrawn's ship, uses it to find Luke Skywalker, and saves him. The next one-and-a-half books can be accurately described as Jade sticking it to Thrawn which eventually leads to his plans collapsing and his death.
Thrawn had figured that she was in a hopeless situation; no one among her old smuggling associates would trust her. This was an error on his part; she was able to convince Aves (one of Karrde's trusted associates) to lend her a Skipray Blastboat and an ysalamir, which she used to retrieve Luke from Jomark (and confront the insane Jedi Master there). Once Thrawn realized his mistake, he was quick to take steps to limit the damage, but the measures (most prominently, the attempt to stop Karrde's escape in Dark Force Rising and the attempt to kill or discredit her in The Last Command) ultimately ended up being inadequate.
The Jennifer Morgue had a very... unique case. Realizing that he is a mad genius billionaire with access to world-ending technology and a strong desire to actually use it, the Big Bad sets up a geas that makes the tropes of a Bond movie reality. He plans to make it so that the only person who stands a chance of thwarting his plan is a solitary British secret agent... and if one of those manages to get through, then he'll shut off the geas so that said agent is nothing more than a solitary man hundreds of miles away from any back-up who can easily be killed. Small problem: despite all his precautions, the Big Bad completely fails to realize by the end that the geas he thought he ended is still operating, even when he's got the hero and his fellow agent bound up and prefers to monologue at them rather than just kill them.
The White Witch could have saved herself a lot of trouble if she'd just killed Edmund as soon as she met him.
But in this case it's justified, since Edmund did not appear to represent any sort of threat personally, and she had a reasonable-seeming plan to use him to destroy her other enemies. She was in fact undone not by a flaw in her plan per se but but by Divine mercy. As Aslan points out, her knowledge went only back to the beginning of Time. She was unaware of key things that happened before that.
At one point she is about to kill him, realizing that he's no longer necessary to her plans, and in the middle of sharpening her knife when Edmund (currently tied to a tree) is rescued.
The only reason the Witch initially kept Edmund alive was because she learned he had two sisters and a brother, fitting the prophecy that two Sons of Adam and two Daughters of Eve would reclaim Narnia, and thus hoped to get all four dead or petrified and be done with it. Her plan almost did work at one point, when the other three Pevensie siblings seriously gave thought to breaking into the Witch's castle to save Edmund, but were talked out of it by the Beavers. She finally gives up on the plan when the three Pevensie siblings reach Caer Paravel thus making their capture impossible, and realizes that simply killing Edmund would stop the prophecy from being fulfilled. By that point, the other assassins she'd sent to kill the children failed, and were used to track down and save Edmund.
Most if not all of the villains in the Twilight series fall victim to this. Probably the most egregious are the Volturi. In New Moon, the only reason they don't want to kill Bella is because she looks like she'll make for an interesting vampire. Instead of just biting her then and there and holding her captive to brainwash her into being a member of their guard (which Breaking Dawn says is what they want from her), they decide to let her go back to Forks, and according to Edward will probably forget about her for thirty years or so, giving the Cullens plenty of time to turn her on their own terms, or hide her. In Breaking Dawn, their goal was apparently to use Renesmee as an excuse to kill the Cullens/force some of them to join the guard. Instead of quickly going to Forks and doing the job, they spend a full month heading over (thus giving Alice a chance to see it and warn the family) and bring a ton of witnesses, which means they have to put on a show of being fair and let the Cullens go. The witnesses aren't even necessary, since Word of God says that the vampires generally accept the rule of the Volturi as right.
In Crescendo, Rixon spends the entire book psychologically tormenting Nora, before getting ready to sacrifice her for a ritual. Given how she's unaware and unprotected for about 99% of the book, that he doesn't manage to pull it off is really astonishing. Nora even asks why he went through such an unnecessary and elaborate ruse instead of simply shooting her in the head while she was asleep. The only answer he gives is that the sacrifice is an important moment, and he wanted it to be enjoyable for him. He then takes this trope Up to Eleven when he kindly holds off on killing Nora while she asks him more questions about his plan, allowing Patch to conveniently show up and save her.
In John Le Carre's spy novels, Karla (the brilliant and ruthless Soviet spymaster) knows how dangerous to his plans George Smiley is but does nothing about it. Even his mole "Gerald" admits as much after Smiley captures him. There are two more novels where Smiley defeats Karla again and again, even leading to Karla having to surrender himself to the West. Karla could easily have assassinated Smiley but never did. He could have gotten away with it, even without a cover plan but (since Smiley had the most unfaithful wife in fiction) he could easily have made it look like a crime of passion like murder/suicide.
However, Karla is not an active participant in The Honourable Schoolboy, and in both Tinker, Tailor, Soldier, Spy and Smiley’s People, Smiley is retired and not a factor as far as Karla knows. In Le Carré’s books, much like the real world (at least at the time) murder is a big deal and something that he would use only under desperate circumstances, such as those of Smiley’s People. There’s no good reason for him to try and have Smiley killed.
Played with in Relativity: A villain named Rasmas manages to trap all of the heroes in a very simple death trap. Unfortunately, he's inside the trap with them when he springs it.
In the Star Trek: Enterprise episode "cold station 12": "Five minutes after we leave, every stasis field in this station will shut down, releasing hundreds of pathogens. I wonder which one will kill you first".
Lampshade hung in a Buffy the Vampire Slayer episode when Harmony captures Dawn in order to get Buffy to attempt to rescue and then capture Buffy. When Harmony's minions point out that they could just kill Dawn because as long as Buffy believes Dawn to be alive then she'll come anyway, instead of waiting until Buffy arrives to kill Dawn. Harmony refuses "Because that's not the plan, duh!".
Played slightly straight when the Master, instead of draining Buffy dry, drinks a little blood from her and leaves her to drown in a pond. Though she was clinically dead, she got revived by CPR.
Charmed would make use of this sometimes as well. The most blatant example was probably 'Engaged and Confused' when, after having two of his associates killed as they tried to kill the Charmed Ones, the demon casually freezes time (an ability he did not attempt to use earlier) so that he and his operative can have a conversation (in front of the Charmed ones) without them knowing about it. He then leaves without attempting to harm the Charmed Ones.
MacGyver uses this constantly, usually in the form of the Big Bad securing the title hero (and usually a pretty lady) in some form of death trap that always has plenty of "useless" items lying around for MacGyver to use for escape. Lampshaded in the episode "The Ten Percent Solution", where a Nazi-lady tries to use a gas chamber on the heroes while a henchman ponders, "Why not just shoot them?"
Happened all the time on Robin Hood. The worst examples were Guy using a half-dead lion to try and kill Robin instead of ordering the fully-armed elite soldiers to just shoot him dead; and later trapping Robin in a dungeon that was slowly filling with water and then...wandering away mid-execution. Robin survives both attempts on his life.
Pretty Little Liars is full of this. A, despite clearly having it in for the all-girl Five-Man Band and having more than enough fodder to ruin their lives with, she takes her sweet, sadistic time. This gives the girls the leeway they need to try and find out who A really is. Most of the time this winds up getting them to fall into A's traps, giving A even more fodder, but it does work to their advantage sometimes.
Subverted in Get Smart when KAOS kidnaps Max, plants a Manchurian Candidate-style hypnotic suggestion in him, then allows for him to escape, making it absurdly easy - and he stubbornly resists escaping several times, convinced he's outsmarting some clever attempts to kill him.
Doctor Who does this during The Dalek Invasion of Earth, when the Daleks restrain two Companions and then leave them to die in an explosion.
Defied by the Master:
"Anyway. Why don't we stop and have a nice little chat while I tell you all my plans and you can work out a way to stop me, I don't think!"
Although he makes just this mistake later on with Rassilon, who has near-omnipotent technology at his disposal. Goodbye Master's masterplan!
In the Smallville episode "Arrival", two evil Kryptonians confront Clark Kent. They open a portal to the Phantom Zone and shove Clark into it. At the last second, Clark grabs a piece of rebar and tries desperately to hold on as the portal sucks him in. Instead of doing something like cutting the bar with their heat vision, the villains just smirk and start walking away, only for Clark to Flash Step up to them, and shove them into the portal.
Power Rangers villains aren't renowned for their intelligence, but were most guilty of Bond Villain stupidity during Power Rangers Jungle Fury, where a constant stream of new villainous overlords continued to defeat the Power Rangers then walk away, only to complain later about not being able to defeat the Rangers. By about the 20th time this happened in a 32 episode show, it was very hard to keep caring.
A few 24 fans weren't too attached to the Affably Evil Jonas Hodges in season 7, because of this trope. At one point in the season, Jones Hodges manages to frame Jack Bauer for the death of a man he tortured by tasering, but could've just as easily killed Jack Bauer in the process. A bit of context: the incapacitated man was lying in the hospital bed recovering from the aforementioned torture when Jack Bauer sneaked back into the room (Bauer wasn't allowed to see him, but had to interrogate him...again). When this happened, Jonas Hodges deployed knockout gas into the room to knock them out for a few brief minutes, which he then sends some men to kill the tortured man, and then leave. This makes the more Genre Savvy fans think, "why didn't he kill Jack while he had the upper hand?" (Answer: because that would be bad for ratings).
The trapmaster in Super Munchkin. He plays a trap card at you when you start fighting him. If he defeats you, however, his Bad Stuff is that "he leaves you in one of his traps and strolls off laughing. The idiot. No effect."
The Hero System features the Psychological Limitation "Over-The-Top Villainy". Villains with this Psych Limit must follow this trope (in addition to several of the other "Overblown Villain" Tropes.
The Infernal Exalted have Acts of Villainy which they commit in order to please their Yozi masters if they've managed to offend them somehow. Most of them have them act in line with this trope - picking a favoured arch-enemy as per Best Enemy Recognition (Foe Yay optional), leaving the enemy to slow death instead of killing them quickly (Fiendish Deathtrap Compulsion), lecturing them about your plans (Infernal Genius Proclamation), leaving clues or sending them straight to your enemy (Insane Death-Dealing Provocation) or just driving people insane for giggles (Kindly Lunatic's Blessing). And it's best to perform as much of them at once as possible.
The explanation for the frequency of this happening in the James Bond RPG is as a result of being Surrounded by Idiots. The villains have huge egos and want to sate them by discussing their ideas with someone who's proven themselves intelligent enough to appreciate them.
Double Subverted in the William Gillette play Sherlock Holmes, where Moriarty's first plan is in fact to just shoot Holmes. He doesn't try it again, though; his next plan involves preparing a Short Con as bait to lead Holmes into a Death Trap (which he escapes in dramatic fashion). Justified, since Moriarty doesn't want a gunshot to be heard outside.
Manny: Is this where you tell me all about your secret plan, Hector? How you stole Double N tickets from innocent souls, pretended to sell them but secretly hoarded them all to yourself in a desperate attempt to get out of the Land of the Dead? Hector: No. (BLAM!) Hector: This is where you writhe around in excruciating pain for about an hour because that idiot Bowsley ran off with the fast-acting sproutella. That slow stuff will sprout you, but it's going to take a long time, I'm sorry to say.
Sephiroth of Final Fantasy VII has this badly. He could, at any given moment in the original game, completely obliterate the party with ease. However, he instead prefers to mock and taunt the heroes, stringing them along with plans to manipulate them later. As is expected with the trope, this came to haunt him later — when Sephiroth kills Aeris, she's already managed to summon Holy, which ultimately stops Meteor's impact. Had Sephiroth just killed Aeris when he had the chance, Holy wouldn't have been summoned, instead he waited for Cloud to catch up to her so he could kill Aeris in front of his eyes to torment him.
Justified to some degree in that Seph wasn't intending to kill Cloud and (most of) his group, it was all part of his plan to get him to deliver the Black Materia to his real body in the Northern Crater, which he then used to summon Meteor.
Subverted though in that she is entirely right about your party being completely unable to stop her or the Alexandrians.
In Final Fantasy X, the three party members who can breathe underwater indefinitely are sentenced to death by drowning in a long but open-ended underwater canal. The other party members have to walk through a monster-infested maze instead.
The reason they were placed there at all and not just executed is because of religious tradition. It's called "The Path of Repentance" for a reason. Also, the bad guys break every Bond villain tradition in the book when they actually realize that this was a bad idea and place guards at the exit.
In Chrono Trigger Dalton, upon first meeting your party: "Hm? Those clothes… You must be the ones the prophet said would come to interfere! I think I shall watch for the time being, and see how he plays his hand. Not that I suspect he'll tip his cards so easily. Ha!" This was a mistake and it was bad for everyone, considering what he does between games...
In Half-Life, a pair of mooks capture the player character and, rather than just shooting him, toss him in a trash compactor; they were under orders to bring him to their commander, but wanted to kill him for killing their comrades, and did it so that his body would be disposed of. Which he then escapes via conveniently stacked-up garbage.
In Half-Life 2, near the end the main character willingly climbs into a transport within the alien citadel that immobilizes him. Naturally, its a trap and it carries him helplessly right to the Big Bad, who does not take the opportunity to shoot him. Justified later when the main villain tries to recruit him.
Parodied in the computer game Evil Genius. In the game, super agents cannot be killed by normal means. When they run out of health, they simply fall unconscious for a few minutes. They can only be defeating by exploiting a specific weakness. So until you figure out what their particular weakness is, your options are limited to locking them up and torturing them regularly to keep their stats down.
In the original Metal Gear Solid this actually is all part of the villains' plans. Because the DARPA chief was "accidentally" killed by Ocelot, the terrorist didn't have the second part of the code to activate Metal Gear, so they needed Snake to progress through his mission and use an alternate means of activating Metal Gear (by making him think they'd already activated it, and that inputting the code would disable it). So locking Snake in a cell patrolled by an inept guard was all part of the plan.
Labtech 123 in zOMG kindly takes the time to explain most of the Big Bad's plan to you, as well as how to override the security system, while he waits for reinforcements.
Played straight for most of the Monkey Island series, with LeChuck dreaming up more ludicrous ways of dealing with Guybrush. In Tales of Monkey Island, however, it gets subverted twice. When LeChuck reveals he was the Heel Face Mole, he kill Guybrush by simply skewering him with a sword. When Guybrush returns in zombie form, LeChuck goes for a No-Holds-Barred Beatdown to try and kill him. When Guybrush asks why LeChuck isn't going for his usual overcomplicated plan, LeChuck informs him he's learned from his mistakes.
In Escape from Monkey Island. LeChuck points out to his villainous cohort that leaving Guybrush alive has always cost him in the past... then they do it anyway. By dumping him on an "inescapable" island that he's escaped from several times.
In Devil May Cry 3, Mission 13 has Arkham detailing his plan in manipulating the twins and his daughter into spilling their blood to undo the seal. He undid the final part of the seal by stabbing Lady with her bayonet through the leg, but it was just as easy to stab her somewhere vital and kill her, which would have prevented her from getting up and turning her weapon on him. ... It also would have stopped her from killing him at the end, too.
This trope is such an essential element of Touhou, with horrifically powerful beings fighting the player character with slow moving, colourful bullets instead of wiping her from existence, that ZUN created intricate justifications as part of the backstory to Gensoukyou. Not only would killing Reimu do Very Bad Things to Gensoukyou (though Marisa has no such protection), not only were the Spell Card rules implemented specifically to prevent that sort of destructive violence (though we don't know if there are any punishments for breaking them), but its denizens are mostly very old, very bored individuals that view fighting as an excellent hobby, and killing their opponent would prevent future encounters.
Jon Irenicus stands out from the norm by averting this trope; not only does he feel no need to explain his plans to you at any point, he also make good use of sedatives to take you out rather than give you a chance to escape, and he makes sure to have you killed off properly after he no longer need you. Unfortunately (for him, at least) he decided to let his sister Bodhi deal with that. She played the trope straight, and had this interesting maze she wanted to test...
Hugo Strange in Batman: Arkham City. Even though he knows you are the goddamned Batman, he doesn't take the opportunity to kill Bats at the beginning when Bruce was unconscious and shackled. He wakes you up and then dumps you into Arkham City without even bothering to track you. And then he tasks an assassin to kill you, suggesting that he wanted you dead the entire time.
Occurs in Knights of the Old Republic 2 when the party is trapped in force cages and a bounty hunter sneaks in to kill you. Even though he could overload the cages to kill you all effortlessly, which your teammate actually suggests, he turns the cages off so he can try to defeat two jedi and one scoundrel in a three-to-one hand-to-hand combat.
Although the dialogue and voice-acting does seem to suggest that this was the bounty hunter's original plan, and Atton's goading bruises the guy's ego enough to change his plans. (Which is still pretty stupid.)
This happens in Resident Evil 4 when the village chief nearly strangles Leon to death but lets him go when he sees he's been injected with a Plagas egg, knowing that he'll eventually succumb to the parasite's control. He later admits in a memo that he gravely underestimated Leon's capabilities and that at the rate he's going, he'll probably destroy the whole village before the Plagas takes over.
Also from the Resident Evil series, Resident Evil 5 shows this in Wesker, who apparently toys with Chris rather than kill him outright. Various cutscenes also depict him grandstanding and effortlessly smacking Chris around, but never bothering to, say, pull out a knife and stab him. One boss fight against him even ends with him simply scoffing and strolling out of the room. Though the general long-term goal is for Chris to end up dead at some point, he doesn't seem to care if Chris is surviving at any given moment and mostly just relishes in tormenting him.
Up until the fight in the bomber, where he finally cuts the crap and starts putting much a more serious effort into killing Chris. A single mistake from that point on is practically guaranteed to be fatal to the player.
Mostly averted in the very beginning of The Elder Scrolls V: Skyrim. The Imperial Legion captured the rebel leader Ulfric Stormcloak and instead of taking him back to the capital and staging an elaborate trial, they immediately take him and the other captives to the next garrison where they are led to the chopping block right after getting of the cart. But even that turned out to be too much of a delay, as a dragon attacks and the prisoners escape in the chaos after just one of them had been beheaded.
Another example would be the various mad scientist-cum-mages who feel the need to have you fight a pet monster of theirs rather than kill you outright, or even Alduin, who, rather than kill you outright when he meets you at dragon burial mounds, resurrects a lesser dragon and lets it do the work. Predictably, it always fails.
Inverted in Max Payne 3, where Max has Becker at his mercy and slowly strangles him rather than just give him a 9mm headache. This gives Victor Branco time to show up. Max does it again immediately by holding off on disarming the newcomer until the first villain is recovered enough to stun him, allowing both villains to escape.
Somewhat justified in that Max is extremely angry and a simple kill shot is too good for Becker, and he's honestly a little surprised at the appearance of Victor, and it takes him some time to process that before he makes his move.
Assassin's Creed III: Charles Lee refuses to kill you in the New York prison, instead explaining how he'll frame you for their own murder plot of George Washington so you are hanged. Connor escapes. When Connor is captured at Haytham's funeral, Lee again refuses to kill him, claiming he wants to break him first. Connor escapes again, this time forcing Lee to attempt to flee the colonies entirely.
Saints Row IV: The Big Bad Zinyak does this to the Boss. Even though the Boss has shown how dangerous he can be to Zinyak's forces, and Zinyak has shown he can easily defeat the Boss in one-to-one combat. He decides that it's better to "break" the boss through a simulation. Considering the Boss's and the other Saint's fierce determination, you can see where this is going. Doesn't stop Zinyak from making the struggle as difficult as possible though.
Halo 4: The Ur-Didact, newly released Sealed Evil in a Can, is a Nigh InvulnerableSufficiently Advanced Alien with powers of levitation, teleportation, and telekinesis. Does he use these powers to quickly kill Master Chief and then resume his evil plan? Nope. Instead he just renders Chief helpless during his lengthy monologues then tosses him away, giving the Chief another chance to stop the villain. Only at the end of the game does it occur to the Didact to teleport to the Chief and kill him himself, and even then he wastes time by suspending him over a chasm and then choking him instead of just dropping him immediately. Then he takes his sweet time yet again even after you've been freed and shoved a grenade in his chest. The guy simply does not learn, does he?
Vaas from Far Cry 3 suffers from this trope badly, succumbing to it at least four times while trying to get rid of Jason Brody. First time he gives Jason a thirty-second head-start and Jason escapes. Second time Vaas gets the drop on Jason, but leaves him to die in a burning building and Jason escapes. Third time Vaas jumps Jason again, and ties him to a concrete block and throws him a pool which Jason escapes from. During this capture Vaas lectures Jason on his beliefs about insanitynote "Insanity is doing the exact same fucking thing over and over again expecting shit to change. That. Is. Crazy.", which may indicate Vaas is aware that what he is doing is just not working but is unable to stop himself. The fourth time Vaas walks up to Jason after a crash and shoots him in the chest, but buries him in a shallow grave without checking to see if he is really dead, missing the lighter that blocked his bullet. During the fifth and final confrontation between Jason and Vaas, Vaas gets the drop on Jason again and stabs him through the chest with a large knife, but something happens, the knife starts glowing yellow, and their last fight talks place in an alternate dimension filled with television monitors. Jason wins, and when he wakes up Vaas is gone and everyone says he's dead.
Generally subverted in the Ace Attorney series, where many of the true culprits in the cases committed murder to prevent word of some other crime they committed from getting out. In fact, given how the playable characters inevitably catch the criminals, one could argue that subverting this trope tends to backfire on them. On the other hand, when the playable characters are forced by the game to do things like be alone with the culprit and show them vital evidence, the culprit's main concern is to destroy the evidence before trying to silence the characters. Given that the evidence is what's needed to put them behind bars (without evidence, it's all but impossible to do anything to them, let alone have them arrested), this makes sense. Not to mention, at least two of those instances are interrupted by the police showing up.
Mass Effect 3: in the Citadel DLC, the Mysterious Figure disposes of you and your squad by locking them in inescapable storage chambers in the Council archives with about an hour's worth of air. Granted, it would have worked if the Figure hadn't forgotten about Glyph, and direct applied violence had failed several times before in that DLC, but it's still not a particularly smart move.
Ultra Fast Pony lampshades the utter absurdity. Unlike in the source material, Night Moon Mare doesn't want to gain anyone's respect or to plunge the world into eternal night. She just wants to kill everyone, yet she doesn't do it when she has the chance.
Night Moon Mare: I could kill you all now, but I'll run away!
Averted in the vampire vs. zombie webcomic Last Blood, during the final battle, the vampires are captured by zombies who chain them up with the intent to torture them. However, for the past 20 pages, there have been allusions to the idea that the leader of the vampires, Addison Payne, has a brilliant scheme to defeat the zombies at some point, even once captured. So instead of letting him live and risking utter victory just for the sake of torture, the lead zombie simply stakes him through the heart, no suggestion necessary. Despite this stroke of brilliance, he still winds up losing it all when he decides to keep one of the human women as his presumed concubine, and goes to embrace her, at which point she promptly stakes him in the heart, killing him and turning his zombies loose.
Edgar in The Aristocats. Gee, leaving a bunch of cats out on the countryside to get rid of them, wonder if they'll find their way back! In Real Life, cats are known to be able to find their way back to their owners from extreme distances, but since Edgar was Too Dumb to Live he probably did not know this. This should explain why he simply assumed the cats would outlive him after taking the old saying that cats have nine lives literally and multiplying nine by their expected lifespan, an assumption that got the plot moving in the first place.
The Great Mouse Detective Professor Ratigan has the ideal situation; bound, demoralized and in a word 'helpless'. He decides to set up a deathtrap and leave. It's justified, however, since he wanted to stay and watch, but had to leave to enact his plans.
Played with in Frozen. The Duke can't justify sending his men out to kill Elsa for witchcraft until after it looks like she did something to Anna, because, y'know, offing another country's queen is a big deal (ice powers notwithstanding). When the "rescue group" finds her, though, Hans, being the Nice Guy he is, tries to peacefully keep Elsa and the soldiers from killing each other. When he takes her prisoner later, even though everyone thinks that killing her will stop the eternal winter, he still promises to try to save her. We then get a very nasty justification. He just saved Elsa to continue to uphold his facade of being a kind, gentle man. In reality, he intended to murder her from the start so he could marry Anna and be king. It was only a question of when he'd do it and, by waiting until he could frame Elsa for Anna's death, he could kill her, take the throne, and look heroic the entire time.
In the episode "The Clock King"'', Fugate, the Clock King, gets Batman in a Death Trap. But he can't resist pulling a Just Between You and Me with a mocking taped message left behind that Batman manages to repurpose into the tools with which to escape. Had he left no message at all, it's likely the Death Trap would have worked, as Batman was ready to try getting out with a cutting torch until Fugate's message informed him that he'd deliberately thought of that already and made sure there wasn't enough time.
Shown clearly in The Fairly Oddparents when Mr. Crocker meets Norm the Genie. They both hold a deep hatred for Timmy Turner, and Norm suggests sending him to Mars, while Crocker tries out a horde of elaborate impractical traps
Played straight then subverted in The Simpsons, where Homer's new employer, a megalomaniac, tries to kill Mr. Bont with such a deathtrap, and Bont escapes, only to be promptly tackled by Homer. Wising up, the guards just shoot him.
In a scene made for the episode where gambling became legal but only shown in a special, a Bond-like character asked the villain to describe the plan but the villain said he wouldn't fall for that again.
In yet another episode, Sideshow Bob was allowed out of prison to help the police to find out who's been trying to kill Homer in that episode. During a scene, somebody asked him why doesn't he simply shoot Bart. The topic wasn't discussed again until the epilogue, when Sideshow Bob did try to follow the advice but found out he grew accustomed to Bart's face.
In The Perils of Penelope Pitstop, the villain Hooded Claw constantly tries to murder the eponymous heroine(ish). The entire episodes are devised of the heroes foiling his extremely elaborate and overly complex homicide attempts. Probably the biggest reason he never succeeded was his need to explain every little detail of each plan to Penelope herself; it always took at least three minutes, and it would either reveal a flaw in the design to her or give her some time to free herself.
In one episode, Slade blackmails Robin into being his apprentice by infecting the other Titans with nanomachines that can kill them literally with a push of a button. Robin gets around this by infecting HIMSELF with the nanomachines, thus giving Slade the choice between killing all the Titans thus removing them as a threat but losing Robin as his apprentice or potentially getting Robin as his apprentice at a later date, but leaving the Titans around to get in the way of his plans. Naturally, as per this trope he does the latter instead of the much more sensible former.
Lampshaded and Averted in the first season finale of Generator Rex. When Van Kleiss gives the order for Biowolf to dispose of a depowered Rex. Rex asks him if he'd rather lock him a cage or tie him to a slab and use a slow moving laser on him, Biowolf simply says "No", and tosses him out the window of the Keep. Interestingly enough, this is played straight later in the episode by the Big"Good" of all people, who chooses not to turn his electromagnet defense system high enough to tear the nanites out of Biowolf's body, but simply to immobilize him for a good old fashioned beat down.
Played straight in the SWAT Kats episode "Night of the Dark Kat", where Dark Kat and Hard Drive have managed to capture the eponymous heroes, but instead of summarily executing them, set them on the end of a long Conveyor Belt-O-Doom that leads to a rock crushing machine, a machine which is wired to blow up the warehouse if shut down, leading to predictable consequences. Dark Kat usually proves more Genre Savvy than that, too. Hard Drive even lampshades it: "I still say you should have let me fry those two!"
Played straight, and not quite Narm, as it IS a kids show and Kids are Stupid, in almost every episode of Totally Spies! or it' follow-up Spies! Instead of actually spying as their occupations imply, it is always the sequence: get tiny bit of info, get captured, Villain explains evil plot, escape, foil.
Played straight in an episode of Justice League when Aquaman's brother, Orm leaves Aquaman and his baby son pinned to a large piece of rock slowly sinking into lava rather than just killing them both outright.
In a similar example to the above Sherlock Holmes example, The Great Mouse Detective has Ratigan set up an incredibly elaborate deathtrap for Basil and Dawson instead of just killing them outright. However, the movie does at least give reasons for why he made it so elaborate (he couldn't decide on just one killing method) and why he left rather than stay to watch their deaths (Basil arrived at Ratigan's hideout later than expected, forcing him to leave early to carry out his Evil Plan). Ultimately justified in that Ratigan probably didn't expect that Dawson would taunt the defeated Basil into creating a plan that set off the trap early and started a chain reaction that freed them rather than killed them.
Futurama pulls this with the Slurm Queen during the 'Fry and the Slurm Factory' episode.
Used and lampshaded in the Phineas and Ferb episode "Nerdy Dancin'": Dr. Doofenshmirtz leaves Perry the Platypus shackled to a table with a slowly approaching laser beam, claiming, "I saw this in a movie once. I didn't catch the ending, 'cause I had other things to do, but it seemed pretty foolproof." Perry escapes as soon as Doof leaves, simply by slipping his small hands and feet out of the shackles.
In The Legend of Korra, Amon has Korra completely at his mercy with about two dozen of his chi-blockers restraining her and looks like he's about to take her bending away and...doesn't. However, he justifies it and only comes across as even more Dangerously Genre Savvy because of it. He needs support for his plan to succeed and this early in the game, taking her bending away would only turn her into a martyr banding everyone not already on his side against him.
Discord, the second-season villain from My Little Pony: Friendship Is Magic, makes this mistake twice. He allows Twilight Sparkle to get her hooves on the Elements of Harmony, since he's corrupted the bearers and rendered them unable to use the Elements, and he leaves Twilight to her own devices in the unraveling Ponyville because he delights in her misery and helplessness. As such, when she regains her confidence, gets her friends back and fighting, and unleashes a devastatingly harmonious rainbow on his face, he's very much taken by surprise.