The Marvel Universe's Thanos of Titan is notorious for resorting to this trope when carrying out his end of a bargain, as a way of "honoring" his word while essentially screwing over other characters. To his credit, Thanos mostly dupes villains (or other similarly shady characters), and as much as possible, honestly keeps his word when he gives it. One notable incident occurred when Thanos promised Mephisto a Cosmic Cube in return for his assistance. Upon Thanos delivering the Cube to Mephisto◊:
Mephisto:Your demise, Titan!(holds up Cosmic Cube) Thanos:(unaffected) Mephisto:(rattles Cube with rage) The Cube doesn't work, Titan! YOU CHEATED ME!! Thanos: I did not. Mephisto, you are already enough of a menace to the tranquility of my universe. I fulfilled my part of our agreement by delivering to you an actual Cosmic Cube. You never specified that you desired a functioning unit. Even devils should beware when bargaining with Thanos of Titan.
When Spider-Man is trying to come up with a plan to defeat an evil Spider-Woman (yes, another Spider-Woman) he asks a man with supposedly ultimate knowledge what can defeat her. He answers "Nothing." This Spider-Woman is a psychic vampire powered by the thoughts of others. By thinking of nothing when they fight she finds she can't feed on them and soon loses power, she is beaten by "nothing."
Doctor Doom is known for this as well. This has allowed him to maintain his reputation for never telling a lie.
On one occasion, he killed a group of musicians for failing to play the "Minute Waltz" in less than 60 seconds. The title "minute" is meant to be the adjective, not the unit of time.
Then there was the time he said that two of his three Doombots were wired to explode. All three blow up. His response? "I never said the third one WASN'T explosive."
He pulled the opposite trick in an issue of The Avengers when he held Avengers Mansion hostage. He warned that they must not attack him because his armor was wired to a Neutron Bomb that would detonate if breached. He actually did have a bomb in his armor, but he was miles away, speaking through another Doombot.
Lobo is a man of his word. His very exact word. Don't piss him off.
For example, there is that one time he was tasked to escort someone alive, something he agreed on... until he found out she was his former school teacher, whom he loathed, and also the writer of an unauthorized Lobo biography, which he loathed even more. Firstly, they said "alive", but not "unharmed", so at one point he cut off both legs of the old lady to prevent her from wandering off. Sure, Czarnians can regenerate, but she was still annoyed. And secondly, when he later completed his duty, he pointed out that he made no promise to not harm her after bringing her back alive... and quickly snapped her neck, definitely positioning himself as the Last Czarnian.
Lobo has also been duped on at least one occasion into failing to complete a contract du to someone else using exact words. Guy Gardner promised Lobo Sinestro's ring in return for him defeating Qward, he did defeat the Qwardian Space Navy, but not the planet itself, so Gardner did not have to pay.
In one Mini Marvels, some Skrulls take advantage of this. A policeman holding the Fantastic Four and Skrull impostors says that whoever can prove who's the real Fantastic Four will be released immediately. The Skrulls immediately admit that they're fakes and prove it by reverting to their true forms. The police officer holds to his exact words unquestioningly and lets them go.
In issue #22, Rick Flag goes AWOL to kill Senator Cray, who has found out about the Squad and is attempting to blackmail Amanda Waller. Waller sends the squad to stop Flag from killing Cray. Deadshot catches up to Flag just as he's about to kill the Senator and instead of killing Flag, Deadshot kills the Senator. When Amanda Waller asks Deadshot why he did this, this conversation comes up:
Deadshot: Said... to keep Flag from.... killing Cray... ANY means possible. Exact Words. Waller: I didn't mean by killing him yourself! Deadshot: Shoulda...said so. I don't... read minds.
And then once he was ordered to throw away his weapons. He agreed. Bullets first.
Unlike many uses of this trope, Deadshot honestly believed the above were acceptable terms. These were not the first signs he was Ax-Crazy, but nobody could ignore them anymore.
Discussed in one of the Marvel comics leading up to Civil War, where Tony Stark coaches Peter Parker on how to answer questions under oath, by not volunteering any information beyond answering the precise question asked:
Tony Stark: Pretend I'm a lawyer. "Mr Parker, do you know what time it is?" Peter Parker: It's 10:35. Tony Stark:Wrong answer. [...] The correct answer is "yes", and you leave it there. If they want more information, let them ask for it.
Roosevelt: Attention, men! Watch out for that north turret! Soldier: What do you mean, sir? A sniper? Roosevelt: No! I meant what I said! Watch out for the north turret! Here it comes!
True of Mr. Mxyzptlk across all his incarnations. This isn't because he's incapable or unwilling to lie, or even because he's purposefully trying to distort the truth. The concept of falsehood is simply foreign to him.
This is subverted after meeting Lex Luthor, who is more familiar with deceit. Mxy's lied once or twice since, but he's usually true to this trope. Luthor and Mr. Mxyzptlk once made a deal that Mxy would keep Superman powerless on the condition that Luthor never tells Superman that Mxy was involved. Believing he could otherwise let Superman know the truth, Luthor told somebody else hoping that somebody would tell Superman. Fortunately, the somebody else was Clark Kent.
In an episode of The Fabulous Furry Freak Brothers published in the 1970s (before cash machines), Phineas Freak was accosted by two muggers who demanded: "Give us all your money!". Interpreting their words literally, Phineas thought of all the effort that would be required in doing this — he and the muggers would have to wait outside the bank all weekend until it opened on Monday morning, so that Phineas could withdraw his savings and give this money to the muggers, among other things and decided he just couldn't do it. The muggers thought Phineas was stoned (which he was), and they left him alone.
In a crossover event between The Darkness and Superman, Jackie Estacado makes a deal with Superman in which he agrees to not kill any members of the rival mob family who have kidnapped Lois. He doesn't. This does not stop Jackie from calling in the other enforcers he brought with him to finish the job.
In the graphic novel version of Neverwhere, the Marquis extracts an hour's Mercy Lead from Croup and Vandemar...except the exact terms were that they "wouldn't touch him" for an hour. This doesn't stop them following him, tearing a ladder he's using off the wall, and standing over his unconscious body counting until they can touch him.
All Fall Down gives us AIQ Squared and his promise that "Nothing *on Earth* is unlawful about what's taking place."
In Empowered, Ocelotina gets a minor Moment Of Awesome using this. Emp has been forbidden from talking about a certain event while it's under investigation, but her teammates have already spread horrible rumors about her relating to the event, so she can't even defend herself without breaking the order. So Ocelotina calls Emp on her show, and then duct-tapes all around Emp's head so she can't say anything and then proceeds to defend Emp in the video. It's nice to see Emp getting some acknowledgement of what was up till then her best Moment of Awesome, even if it is from a mixed-priorities fan.
In Mortadelo y Filemón, if Mortadelo is asked to check for any guard dogs, he won't say a thing about the hungry crocodile... And if he says there is "nothing" behind a door, don't go rushing through it too fast...
In Mega Man #4, Mega Man is in a deadlock against Dr. Wily's Copy Robot, when the recently-revived Robot Masters barge in to carry out their orders by destroying Mega Man. They do... by destroying the Copy Robot while the real Mega Man hides up above on his Magnet Beam. Mega Man, aware that these Robot Masters were trying to kill him not too long ago, is confused, until Elec Man explains their actions:
Elec Man: It's just like you said. You were programmed to help people, so here you are fighting. We were ordered to destroy one Mega Man. Mission accomplished.
New 52: For extremely complicated reasons, Wonder Woman agrees to marry the god Hades. Hades, suspecting some kind of trick, ties her up in her own magic lasso as she says that she loves him, so he believes her. A short time later, Wonder Woman betrays him. Hades incredulously asks how she could lie while touching the magic lasso. Wonder Woman says that she never lied, she loves him, just like she loves everybody.
In one Richard Corben story in Heavy Metal, a swordsman and his female adventuring partner are on a quest to track down and slay a necromancer. They get separated, and when the man finds her he's too late, and she's already a zombie...but the necromancer is lying dead nearby with a split open skull, and there's a goat wandering around. The woman tells him that he zombified her and then made her help with a sacrificial ritual, holding a goat, giving her a sword, and saying "When I nod my head, strike it!" She explains "He... nods head... I… strike it!"
Dredd pulls one on Mean Machine Angel in the Three Amigos storyline. Dredd agrees that in exchange for Mean Machine's help, he'll release the Angel gang from Mega-City One, free to do as they please, on the understanding that if they try to enter the city again they'll be arrested. Dredd keeps his word, but he releases them from the east exit, on a tiny patch of land surrounded on all sides by the highly-polluted Black Atlantic. The Angels have nowhere to go except back into the city…where he arrests them.
He will frequently use this method as a means to 'trick' criminals in some way. For example, reducing a mook's sentence of 20 years by 1 day, in exchange for them having betrayed their boss, on the basis that he kept his promise to 'shorten jail time' in exchange for information. He's also fond of promising criminals he'll "consider" letting them off the hook. No points for guess how that one plays out.
In "The Strange Vow of Robin Hood" from Robin Hood Tales #9, Robin vows not to set foot on English soil until he recovers Richard's ransom. He believed the money was stolen by Norman pirates, but soon learns that in fact the money is being held by the villainous Baron Grote in England. Robin refuses to break his vow, and travels to the robber baron's castle by swinging through the trees, rolling down a river in a barrel, and rides on a stage. When he gets near the castle, he's helped out by a passing draper who rolls a long carpet straight to the castle door.
Partially inverted by The Riddler as in several instances his true agenda or solutions to his deadly puzzles can often only be obtained by examining what he says for double meanings or alternative interpretations.
In My Little Pony: Friendship Is Magic (IDW)Chrysalis promises Twilight that she would not hurt or drain her friends if Twilight promises to become Chrysalis's apprentice. However, Chrysalis never said Twilight couldn't be made to hurt them.
In X, the first mark is a warning. The second mark is death. If the X is completed on your face or an image of your face, then the X-killer will kill you, even if he wasn't the one who put it there.
In an Iron Man storyline, Doctor Octopus holds the city hostage with a nuclear bomb, just to force Tony to say he's not as smart. At the end he reveals that it's nuclear, but isn't really a bomb, and points out he always called it a "device". Subverted when a perplexed Tony says that isn't true, and Ock replies, "Who cares? I Lied."
Lucifer. Since he Will Not Tell a Lie, ever, he resorts to telling people the exact, literal truth and not one iota more than is needed to make them do what he wants.
Roy of the Rovers was once given a challenge by a millionaire to score 40 goals in a season, after which the millionaire would make a big donation to Roy's favourite charity. In the last game of the season, Roy had scored 39, but Rovers were being forced to defend. Roy botched a clearance and scored an own-goal. But, as Roy pointed out, this met the millionaire's challenge, which had said nothing about the goals all being scored for the right team.
In one issue of G.I. Joe Special Missions, Cobra agents steal the Vector fighter jet and the software of the Skystriker and Conquest jets at an air show. The Vector's pilot, Maverick, gives chase with a stunt pilot in a biplane. At the end, they recover the Vector, but the stunt pilot's biplane is confiscated for an illegal landing. He says he'd ask Maverick for a ride, but there's probably a lot of regulations against that sort of thing. Maverick confirms that there's a regulation against giving civilians a ride in military aircraft...but there's no regulation against letting civilians fly the plane themselves.
When T'Challa attempts to recruit the X-Men for help during the events of the Doomwar arc, Cyclops says that he cannot sanction X-Men involvement as it would make them look like global aggressors. However, he later confides that that doesn't mean he would stop them going of their own accord. Sure enough, Wolverine, Colossus and Nightcrawler are already packed by this stage.
Later in the same arc, the final lock on the vibranium vault is described that "Only by purity unencumbered by pretence shall you pass". To everyone's shock Doctor Doom manages to open the lock, because he is purely committed to his evil goals.
In New Avengers, Captain America tries to get Black Panther's backing when he decides to go against The Illuminati's plan to destroy another world in order to protect their own. When Cap asks if he has the Panther's support, Panther responds by saying "Have you ever known me to not do the right thing?" It turns out the "right thing" in this case is siding with the Illuminati against Captain America in order to make sure Wakanda is saved, and Cap ends up being Mind Wiped for his troubles.
In the Greg Rucka / Michael Lark series Lazarus, the protagonist Forever Carlyle went through Training from Hell as a young girl, including brutal hand-to-hand combat and (wooden)swordfighting training with a woman that she nevertheless cared for a great deal(said woman was one of the only people who treated Forever like a person and not a weapon being forged). In order for Forever to be allowed to carry the Carlyle family sword, her father Malcom orders that she have to defeat her mentor in a sword duel. He shows up to supervise the fight but raises the stakes by having them use live steel blades instead of wooden training swords. Forever manages to injure and defeat the older woman, but stops fighting once she's down. When Malcom asks why she held back, Forever reminds him that his orders were to defeat the woman, not kill her. In an inversion, Malcom congratulates her for obeying his orders and rewards her with the family sword.
Fantastic Four: in an early storyline, Mr. Fantastic, Thing, and Torch are sent back in time to retrieve Blackbeard's treasure or Doctor Doom will kill Sue. Mr. Fantastic decides to dupe him, saying technically they promised to bring back the treasure chest, so even if it's a chest filled with chains they've fulfilled their word.
Doom for his part had promised Sue's safety but not the rest of the team's
In the Fantastic Four/Superman crossover, the Cyborg Superman — who manipulated the events of the comic book — tells Galactus he wants perfection. Galactus obliges, turning him into a block of metallic alloy, which Reed notes is perfect in every way.
Darth Vader and the Ninth Assassin (not to be confused with Star Wars: Darth Vader) has an exchange between a bounty hunter and his client that goes like this: "You will know of my success what you have Vader's head on your lap. You will not see or hear from me again". Cut to the other guy sitting in a chair, his eyes and ears removed. Touch is the only feeling he has left.
In Pierre Tombal, the titular character found a revolutionary way to gather donations: put a "book that contains the names of a lot of people who will die in the future", and tell to people who pass by that "they can have it if they put whatever they want in that urn for the charities of this graveyard". The book turned out to be the phone book. Everyone will die some day, so all the people listed in the phone book fit that bill.
In the spy comic Deceivers, CIA agent Patrice Andauer tracks down a couple of con men, Lincoln Mc Cord and Janez Nikovic, and tells them about an international thief known as Ulysses who has been stealing documents from various high-up intelligence agents. She says she 'has reason to believe Ulysses is standing right here, right now'. Both of them deny it and assume it's the other one, and the question of Ulysses' identity drives the plot, with various criminals and spies going after the two of them. In the final issue it's revealed that Patrice was telling the truth: she is Ulysses..
The Black Knight: At the end of his first appearance, Scrooge makes Arpin Lusène (who's a Gentleman Thief above all else) promise that he won't pick Donald's pockets to steal the key to escape his restraints. As soon as he's offscreen, he steals Donald's whole outfit instead.
Exact words don't get much more exact than in the Preacher one-shot volume focusing on Jody and T.C. At one point during the story, they go to a backwoods version of a fight club, where two guys jump into a pit and fight it out while spectators bet on the outcome. Only problem is, no one will bet on a fight with Jody in it, because it's sure that Jody will win. However, the guy who runs the fight club says that he's found a "real gorilla" (usually slang for an extremely muscular or savage guy) to fight Jody. So Jody agrees and jumps into the pit without seeing his foe. Then the manager of the fight club brings a cage over and opens it so the angry gorilla inside jumps down into the pit, resulting in Jody's dry observation "Ah. So when you said you found a real gorilla, you meant a real gorilla."
In Superman and Spider-Man, Doctor Doom monologues that Superman is always welcome to visit Latveria and see how utopic it is. Superman reasons that since Doom is the head of state, that means he isn't violating any laws when he flies to Latveria to investigate Doom's current scheme. As it turns out, this is just what Doom was hoping would happen.
In Loki: Agent of Asgard, Old!Loki comes from a future where Asgard is perfect, but the price was that Loki returned to being a villain. When unable to lie, he assures the All-Mothers of this. When they ask about Midgard he says "'Twas governed most perfectly, by my reckoning". It doesn't occur to anyone to ask what someone who isn't evil might think of it. It's a dead world. Or to ask who governs it so most perfectly. Loki is the "King" of Midgard in that timeline, and what else would Loki ever judge his own rule? Loki is many things, but humble is not one of them.