There are many ways a first encounter with an alien race could work out. Maybe they're a Horde of Alien Locusts and wants to eat us, not talk with us. Maybe they want us to prove that we're really intelligent by doing math. Or maybe they just speak English like everybody else.
But if the aliens really ARE 'alien', it's far more likely that somebody will horribly misunderstand something. Maybe it'll be us, maybe it'll be the aliens, but either way, it'll probably turn into a horrific war and everybody will feel really bad about it all afterwards, when the smoke clears and we finally get things straightened out.
- The central conflict between the Vajra and humanity in Macross Frontier was started by this. The Vajra mistook humanity for a broken Hive Mind because Humanity Is Insane, and 'rescued' what they perceived to be the queen bee in the hopes of helping her. From humanity's perspective, however, their princess had just been kidnapped by a Horde of Alien Locusts, and the Bug War was on...
- In Gundam 00: A Wakening of the Trailblazer, the conflict between the Extra-Terrestrial Living-Metal Shape-Shifters or ELS and the Earth Sphere Federation Army takes place due to the former's inability to communicate with the Earth. They stop after Setsuna uses his Innnovator status to tell them of their actions.
- In one story of Doraemon, a mini alien scout ship is sent to earth and comes across Nobita and Doraemon happily watching a show where aliens get beaten up by Sentai, thus making the alien in the ship conclude that Humans Are Warriors, so violent that the rest of his kind should not make any further contact with. The Irony is, said aliens are created by Nobita and Doraemon specifically to have them develop their own civilization and make First Contact with humans.
- Invoked and Subverted in Attack on Titan, in a non-alien example of First Contact. Cloud Cuckoo Lander Sasha innocently asks Onyankopan, the first Black person she's ever seen, why his skin is dark. She's clearly unaware that such a question is extremely rude. As such, he laughs it off and explains that God thought it would be more interesting to make different kinds of humans.
- Plan 7 of 9 from Outer Space
- A screeching Giant Spider lands on the White House lawn and is promptly incinerated by the military. According to the uni-vocal translator the screech meant: "Strange two-legged beings, I greet you in the spirit of intergalactic friendship."
- Captain Proton offers to shake hands and is Mistaken for Gay, because the aliens have heard that Holding Hands is a sign of romantic affection on Earth.
- When the Governor of California wants to speak to the aliens, this is rejected as his First Contact procedures leave much to be desired. "As I recall the first thing he said to one extraterrestrial species was: 'You are one ugly motherfucker'."
- Turns out Anal Probing was an attempt by the Martian race to make First Contact with humanity. It was supposed to be a Mind Probe, the assumption being that humans had their brains in their behinds.
- In the Star Trek: Enterprise Parody Fic "Next Week on Enterprise", Captain Archer makes first contact with the Deltans, but their Dirty Mind-Reading reveals he thinks of them as "the Sluts of the Universe". The outraged Deltans inflict him with the Curse of Delta IV, making all Starfleet captains bald and horny for generations to come.
- Pixels: aliens misinterpret a probe containing 80s arcade games as a declaration of war.
- Octavia Butler:
- Bloodchild features the T'lic treating humans as cattle before realizing it's not a very sustainable method of hosting their young safely.
- Amnesty features the Communities kidnapping individuals and attempting to experiment/communicate with them, but abusing them due to a lack of understanding.
- This seems to happen a lot with Bee People in general. Ender's Game features the hive-minded 'Buggers', who also wound up at war with humanity over a misunderstanding regarding the first human scout-ship to encounter them. Lacking any individuality and having no sense of self beyond the 'hive-mind', they regarded the destruction of a handful of scouts as barely worth noticing, and humanity's reaction (including the death of one of their Queens) as Disproportionate Retribution. In the end, they figured out what had happened, and were horrified to realize what they'd done - but by then, it was too late to stop humanity (read: Ender) from nearly wiping them out. When he afterwards found out that they had no ill intent, he wound up dedicating the rest of his life to helping what little remained of their species.
- The sequel to Ender's Game, Speaker for the Dead picks up in a future where humanity has learned the Buggers/Formics had peaceful intentions and so are determined to avoid the same mistake of miscommunication with the next alien species they discover. But they go too far in the opposite direction, ordering their scientists studying the "pequeninos" to tell them little about humanity and only observe the aliens instead of interviewing them. Thus misunderstandings occur because the aliens are unfamiliar with human biology and assume it to be like their own, resulting in several humans dead from ritual vivisection. For the pequeninos, the act is a great honor because it triggers the reproductive stage of their life cycle; humans just die.
- In The Conquerors Trilogy by Timothy Zahn, humanity's first contact with the titular alien race turns vicious when the aliens open fire without responding to the humans' hails, and after a Curb-Stomp Battle proceed to Sink The Life Boats. In the war that follows, the humans claim that the Conquerors shot first, but the aliens insist the exact same thing. It turns out the Conquerors are extremely vulnerable to radio frequencies, and interpreted the messages of friendship that human ships sent out as an unprovoked attack, and the life pods' distress beacons as additional weapons. It's a problem the aliens have run into a lot, apparently.
- In the third book of the Ark Royal trilogy it turns out that the reason the aliens are attacking is that a human group colonized a planet that was already settled by the (aquatic) aliens. But neither species knew of the others' existence until one alien happened upon a couple teenagers, who freaked out and shot it. The aliens have to debate everything with practically the entirety of their race before deciding on any action, so they thought humanity was invading.
- In the Peter Watts' novel, Blindsight, human communications are so alien to the first aliens that receive them (i.e. from radio and TV transmissions), that they consider humans a virus and immediately set out to destroy them.
- In The Forever War some of humanity's colony ships disappear without a trace, then aliens they can't communicate with are encountered in the area. Earth assumes they're responsible and declare war. A thousand years of war later they figure out how to communicate and find out the aliens know nothing about the lost ships. From their point of view, humans fired the first shot.
- The aliens are also Bee People who don't understand why humans are so upset about losing a few expendable Contact units.
- Halo: Contact Harvest describes the events that kicked off the Human-Covenant war of the Halo series. The Covenant are artifact seekers searching for relics of the Forerunners they worship, but a strange reading identifying the human colony Harvest as having thousands of relics causes some Covenant to launch an initial skirmish thinking humans are keeping the treasures for themselves. An attempt at peace talks is made, but broken by a trigger-happy Grunt. Within that week, the battles at Harvest turn from a mere mis-communicating tussle to government-sanctioned genocide when the leaders of the Covenant secretly discover that humans are in some way related to the Forerunners (hence why their sensors keep on identifying humans as Forerunner relics), the implications of which show their religion to be a complete lie. Hoping to keep their discovery under wraps and so not shatter the Covenant's foundation, they order humans to be wiped out and so begin the series' long war.
- In the short story "Tableau" by James White, a prequel to his Sector General series, humanity's first contact with an alien race is with the Orligians, who resemble animate teddy bears and travel in family groups. During their first face-to-face meeting, the captain of the human ship demonstrates his friendly intentions by embracing an Orligian child... unfortunately, Orligians don't find humans so cuddly, and in fact are reminded of a primitive predator on their own planet which frequently goes after children; they think the captain is attacking their child, and counterattack, wiping out the human crew and igniting a war that goes on for years.
- In the short story "As Wise As Serpents" by Stephen Dedman, an alien visitor slaughters the party of high-ranking dignitaries welcoming him to Earth, apparently unprovoked. It was the first time he'd seen humans wearing neckties, and his species has an unhappy history with a Puppeteer Parasite that latches on to its victim's throat and dangles down the victim's chest... Fortunately, in this case, the protagonist figures out the confusion before things escalate into outright hostility.
- In another short story (title and author unfortunately forgotten) humanity winds up in an ugly war with a race of Cat Folk after one of the military honor guards for the human party (it's not exactly first contact, but it is the first official diplomatic meeting) turns out to have a very bad cat dander allergy. He sneezes all over the cat-aliens' top leader, the cat-aliens start shooting, and a page later it's a major interstellar war. It's actually implied at the end that this may have been arranged by, or at least not entirely undesired by, human leadership; it's mentioned that the human fleet was suspiciously well-positioned to act as soon as hostilities broke out.
- In the Foreigner series humans initially had no idea that the atevi have no conception of borders. As a result, humans who thought they were dealing with a single group of atevi were actually double-crossing and triple-crossing multiple groups, which eventually led to a war that almost wiped out the human Lost Colony.
- In James Cambias' A Darkling Sea, the first contact with humans by Ilmatarans involve the Ilmatarans capturing and dissecting a human who's trying to observe them close-up in secret and screwed up, not knowing that humans are sapient. Weirdly enough for this trope, the ensuring conflict isn't with the Ilmatarans, but with another spacefaring species, the Sholen, who humans are pretty much forced to sign Alien Non-Interference Clause treaty with. In fact, later on a proper first contact is established between Ilmatarans and humans via First Contact Math.
- This turns out to be behind the mystery in Infinity Beach. The aliens were much smaller than humans, and panicked and opened fire when they thought they were being trapped. The mistake was then covered up by the crew, and later the authorities who were worried about how the aliens might react to the news that humans had killed their kind.
- In Babylon 5, the Earth-Minbari war began due a series of faux pases on both sides. An EarthForce squadron enters a Minbari system that they believe is neutral space. Upon discovering alien ships, the commander ignores First Contact protocol and starts using an active scan on the Minbari ships. Unbeknownst to them, one of the ships is carrying the Grey Council, the Minbari government. Showing remarkable patience, the Warrior Caste satai (member of the Grey Council), who happens to be in charge at the moment, orders the ships to activate the stealth system and scan back at full power. He had no way of knowing this would jam the sensors and jump drives on the EarthForce ships. The Minbari ships then approach with all gunports open, a gesture of respect and peaceful intent in their culture (you can see everything they have). Captain Jankowski of EarthForce, not knowing of this tradition, mistook it for an aggressive move and sent messages that they came in peace. But he called them in English, that the Minbari could not understand, and when they did not respond and a power spike on a Minbari ship made it look like they were charging their weapons he ordered them to open fire. The attack killed the Minbari leader, and in their rage the Minbari started a drawn-out war that left people on both sides feeling terribly guilty.
- In the Doctor Who story "The Ambassadors of Death", something unclear went horribly wrong when an unnamed alien species first encountered humans, with two of the three astronauts involved being killed and the third becoming a vengeance-crazed psychotic. This was probably related to the aliens' extreme biological incompatibility with humans - they are radiation-eaters who even communicate by exchanging short coded bursts of hard ionising radiation, and a friendly greeting from them fired directly at a human causes instant death.
- Star Trek: The Next Generation. Captain Picard states that a disastrous contact with the Klingon Empire led to decades of war (unfortunately this is contradicted by the events of the prequel series Star Trek: Enterprise where the Klingons are often hostile, but not to the extent of waging war).
- Star Trek: Enterprise. Captain Archer does run into this trope however, because Starfleet lacks experience and Earth is regarded as an Insignificant Blue Planet. The B-plot of one episode had delegates of a newly encountered alien race being offended after being given a tour of Enterprise, storming off after ten minutes. It ultimately turns out that what offended them was being shown the mess hall, as the thought of communal eating is repulsive to them. Eating and personal displays of affection should be conducted in private.
- Star Trek: Voyager has a couple of amusing Noodle Incidents mentioned where an Accidental Unfortunate Gesture led to this trope.
- A The Far Side comic features aliens with heads shaped like outstretched hands. They land on a farm, and the farmer thinks they're offering to shake hands... The caption notes that he inadvertently doomed humanity.
- In Son of Cliché, the radio precursor to Red Dwarf, a luckless Red Shirt crewman gets to make First Contact with apparently friendly aliens. After a squicky discussion of alien reproduction and a revelation that the aliens have met Earth people before:
Alien: You must know Jan van Raavens? He's human too. From your Hoh-land? come on, you're from the same planet. You must have met him. No? [...] There is one final formality to establish friendship. Come, Earthman, we must now exchange heads.
(swishing of steel blade, meaty thump, spurting noise and the thud of body hitting ground)
Alien: Funny, that's what happened to Jan van Raavens...
- A somewhat more straightforward faux pas: First contact between the humans and VUX in the Star Control universe went sour when the human captain reacted to the appearance of his VUX counterpart with the memorable words "That's the ugliest freak-face I've ever seen!". Unfortunately, the mic was on. And the VUX had very, very good translation technology. Amusingly, you eventually learn that yes, humanity looks just as utterly hideous to THEM as they do to US, with one of them blithely admitting that he can barely restrain himself from throwing up whenever he sees you on his monitor.
- Mass Effect:
- The "First Contact War" between humans and turians was a small three-month war that started when some turian police cruisers encountered human ships attempting to unseal a mass relay, which is banned by the Citadel Council but humanity hadn't known that. Fortunately the Council was able to negotiate peace.
- When the Citadel made first contact with the Yahg, they made the mistake of trying a peaceful approach. The Yahg were offended that the Citadel delegation didn't try to fight them, and thus they killed the delegation. The Citadel promptly ceased any further efforts to communicate with the Yahg.
- One trailer for the game has humanity launching its first warp-capable starship towards a star that hosts life. The locals repeatedly warn it to stay away but the human ship doesn't understand and is destroyed. Fortunately the aliens learned English from salvaging the wreckage and were able to explain things to the rescue party.
- One anomaly your science ships might discover is a coffin from a Burial in Space containing a dead alien. If you decide to pop it open for study, it's possible that the next alien species you meet will reveal that you just desecrated the remains of one of their greatest heroes, which will put a strain on relations, to say the least.
- It's also possible to do this by colonizing worlds without fully exploring the space around them, by, say, settling an enticing planet that happens to be one of the Holy Guardians' sacred worlds, or grabbing a system that turns out to be next to some Militant Isolationists. One minute you're managing a production queue for your new colony, the next you're receiving a transmission from an irate Fallen Empire demanding that you remove yourself from their world before they do it for you.
- Sword of the Stars has this as the default when making contact with aliens. Being not at war requires researching the species. Whenever ships meet combat will begin - although it is thankfully possible to flee without inflicting any damage to avoid doing damage to relationships once established.