It is such a friendly, peaceful little place.
In spite of being surrounded by the big malevolent empire, and technically being at war with it, the village is not the least bit warlike or aggressive. Yet the empire keeps sending its great legions, and the little village keeps crushing them all as if they was simply swatting flies. Perhaps it is a Town with a Dark Secret, or populated by Badass Crews, or maybe a Knight Errant visited in the past and took to Training the Peaceful Villagers. Whatever the reason, it's practically invincible.
While the "village" can be some other form of small civilian community (a block in a city, for example), it must still be small and civilian. Military outposts do NOT count, and neither do entire cities or full sized countries. So, no, 300 is not an example.
While the "Empire" can be some other form of huge monolithic force (a megacorporation or international crime syndicate, for example), it must still be huge, powerful, prone to violence, and known for conquering all in its way. A single country, normal corporation or criminal gang will not do.
Compare Hidden Elf Village, which stay independent through not getting detected instead of crushing all the hordes the empire sends against it. Compare and contrast The Remnant, which is rarely depicted heroically. Also compare David vs. Goliath. Frequently caused by a Superweapon Surprise.
- Asterix is the Trope Namer. The Gaulish village is not the only case: there are similar undefeatable little villages in Britain and Spain (which is lampshaded by Caesar, who is sure he had seen something like that somewhere else). Corsica is only nominally under Roman rule: yes, there are Romans there, but they are completely incapable of making the Corsicans do anything (be it accept a Roman registration of the house, or just load some boxes onto a ship). This is quite Ironic, as the earliest known example of this trope was a Roman city assaulted by a mostly Gaulish force (see Real Life below).
- From a cosmic perspective, planet Earth may be counted as this in the Marvel Universe. A tiny planet which has not even colonized its moon, but has resisted time and again against the Kree Empire, the Skrull Empire, the Shi'Ar Empire, Ego, the Phoenix force, the Celestials... and even drove Galactus away, and humbled him near to death.
- In the Fables album "The Good Prince", The Empire is severely shaken by such a village, having sent more troops against it than it could afford to lose.
- The Smurfs' Village is always facing terrible (for them) enemies like evil wizards, giants, predators, etc.
- Seeking the supersoldier Frank Simpson, Ultimate Captain America seeks the hidden village of Saloth, in Vietnam. He finds it, but there are no adult men: just children, women and elders. One of those elders told cap that he's not the first big and strong guy who shows up giving orders, but that they defeated all the previous ones and used them to feed the pigs. Cap ignored him as a senile folk... and then discovers the secret: the children, women and elders are all super soldiers.
- The tiny Korean village of Sinanju is this in the Destroyer novels, despite being a dreary, squalid little place, full of dull, lazy, not-so-bright people. Being the home of the world's most dangerous line of Assassins counts for a lot.
- For a time, Emond's Field in The Wheel of Time became this trope, fighting off way more Trollocs than it had any right to using little more than skilled archers and a sheer stubborn refusal to lose. It only stopped qualifying because being one of the few stable places in the world afforded it massive immigration, causing it to grow into an undefeatable little country.
- Pretty much the entire premise of the Redwall series.
- Somewhat more justified than most other entries, while Redwall's inhabitants are mostly peaceful creatures the abbey itself is a fortified castle built to survive a siege. It has it's own orchards, gardens, fields and a freshwater pond with edible fish living in it; their stores are usually well stocked with fresh and preserved food and a full wine cellar. As pointed out in the first book, Redwall is virtually self-supporting. The few times vermin get inside the abbey is mostly defenseless, it's getting inside that's the hard part.
- The science fiction story "Microcosmic God" by Theodore Sturgeon posits a scientist living on an island creating a population of small, intelligent creatures that live short lives in an ammonia environment in tanks in his lab. He communicates with them through a teletype connection (it's an old story). They make many great inventions for him because their generations are short in time, so many generations can work on a problem. The outside world wants them, so the navy is poised to attack him. He requires his creatures to build a completely impregnable shield around the island, which they do. The navy spends the rest of time bombarding the grey sphere, and he spends the rest of his days with his creatures.
- The small mining town of Grantville is somehow transported back in time from the year 2000 to 1632. The civilian population is able to withstand multiple attacks from the surrounding 17th century states since the "Uptimers" have access to modern weapons and technology. As the series progresses, this trope no really longer applies, as they start to expand beyond their original borders.
- A neo-nazi version is Kinsland in David Lane's novel KD rebels, which is a small mountain area taken by white supremacists which somehow are capable of keeping the United States federal government at bay. The title itself is an acronym for "Kinslad's Defense". Although instead of defense the main protagonist kidnaps two white striper girls to be his (at first) unwilling wives... (yes, is that kind of novel).
- This trope ended up undermining the Warhammer "Storm of Chaos" campaign event back during the game's 6th edition. Games Workshop billed it as a chance for players' battles to have an impact on the story of the largest Chaos invasion in history, when the dread hordes of Archaon the Everchosen would attempt to crush the Empire once and for all, with the Siege of Middenheim serving as the grand climax. The problem was that the results indicated that Archaon's forces couldn't take even the first insignificant border hamlet on the campaign map. So when the first narrative update came along and declared that said village had been effortlessly flattened, some players got a bit annoyed that their battles didn't count, which probably contributed to the whole event being rendered non-canon by subsequent material.
- In Risk Australia is considered to be almost impossible to take, due to there only being one way in. Anyone who takes Australia and starts building up there is going to end up almost completely impossible to dislodge.
- Although Asterix comics are one of the best-known examples of this trope, the video game adaptation for PlayStation strays away from this by having the player take back the Gaulish territories.
- In Heroes of Might and Magic III, the town of Fair Feather fills this role in the campaign mission "Guardian Angels". As the name implies, the reason for the town's survival is because Angels are guarding the town, which the player can recruit and promptly turn the whole mission into a cakewalk.
- In Fallout 3, you can train Big Town to be one.
- Fallout: New Vegas:
- Goodsprings is one of these, if you decide to help them drive away the Powder Gangers. If Caesar's Legion wins, and provided you didn't help the Powder Gangers destroy the town, the Legion passes up on conquering the Goodsprings, despite going Rape, Pillage, and Burn everywhere else in the Mojave. Though, this may be a case of Not Worth Killing, since they're a town of 20 ranchers in a tactically unimportant location.
- Nobody except Legate Lanius dares to mess with the Boomers, considering they're inhabiting Nellis Air Force Base and thus have howitzers, assault rifles, missile launchers, mini nuke launchers, and eventually a WWII bomber on hand, and blow anyone who tries to approach them to bits.
- At the beginning of Shadow Hearts: Covenant, the village of Donremy, France fits this, because Yuri is there. Once Yuri is cursed and has to leave, it falls to the German advance.
- In Arcuz, the titular village appears to be this, given the lack of other (visible) towns. The intro sequence seemingly hints that they were all destroyed.
- It is possible (though very difficult) to be this in Crusader Kings 2. If you only have control of one county, then you are essentially crippled with an inability to raise any significant military forces in the event that you get attacked. However, if you play your alliance cards right, then you can call on allies in the event you get attacked and have them defend you. Given that the point of the game is to amass power and influence, however, it's not a winning strategy.
- In the Shantae series, Scuttle Town has proven difficult to pillage for Risky Boots, since it's protected by the title half-genie. Naturally, the town immediately gets imperiled any time Shantae is on exile or held up elsewhere. It's only left alone when Risky goes to the same island resort Shantae is vacationing in.
- During an arc of Sluggy Freelance, it's revealed that a small town near the Canadian border ended up playing this role for a crime-syndicate who had, previously, used it as a center for their smuggling operations. The reason? Knife Nut Tyke Bomb Quasi-Immortal Oasis, whose most recent reincarnation had turned out unusually sane and kindhearted, had made it her Protectorate. Wearing a red hoodie, she turned into the vigilante 'Red Riding Hood' and simply stabbed any criminal who dared enter the city. The syndicate finally sent a top-tier, highly-paid Professional Killer - a master assassin. He managed to kill her, but obviously didn't know about the 'Quasi-Immortal' bit, and wound up getting stabbed anyway. He sought alternate employment with great rapidity at that point.
- In Looking for Group, Pretty Pretty Unicorn appears to fit this trope until the arrival of missionaries and soldiers from the empire, at which point it's revealed to be populated by an undead Badass Crew and houses the Power Source of an all-powerful warlock.
- The village of Felton tries to be this in the AlternateHistory.com timeline "Protect and Survive: A Timeline". It fails. Choose the fucking cowboys. Especially when they've got a fucking tank.
- Felarya has Safe Harbor, which has weathered a series of attacks by man-eating predators, hostile humans, and other ills. It owes its continued survival to Jade, a badass giantess who absolutely destroys anything that threatens it.
- The Celtiberian settlement of Numantia has to count as the chief example, to the point "Numatine resistance" was for a long time Spanish jargon for defending a hopeless position to death. While small and poor for Roman standards (it's said they could grab few to no spoils after conquering it), it resisted alone the advance of their armies for years, and its conquest marked the end of the Celtiberian Wars.
- The Italian city of Cremona started out as one, and the oldest example on record: founded by the Romans as a colonia (a town in recently conquered territory, with a large civilian population to show the benefits of Roman civilization and a garrison for protection) in Gaul-inhabitated northern Italy shortly before the Second Punic War, the arrival of Hannibal and his army caused a general revolt of the local populations, leaving Cremona cut off and besieged for years until the Romans turned the tide. Her twin colonia of Placentia barely missed qualifying, as the Hannibal-aligned Gauls ultimately managed to burn it down-after eighteen years and Hannibal leaving Italy and being defeated at Zama getting them to lower their guard, with the Gaulish army eventually being wiped out the following year when they tried to attack Cremona and found pretty much Rome's entire military waiting for them.
- Buenos Aires, in Argentina, during the wars of independence of the 19th century that involved the whole of Latin America. There were patriots and royalists, similar to the patriots and loyalists of the US of some decades earlier. Some cities had patriot revolutions but were recaptured and then liberated again (Santiago, Sucre, La Paz), and others stayed as royalist strongholds for some time, resisting against the patriots, until the patriots finally prevailed (Lima, Montevideo, Asunción). Buenos Aires had its revolution as early as 1810, and it was never recaptured. There was even a time by 1816 that only Buenos Aires and its areas of influence were still free.
- Brazil's Canudos village, which repelled three invasions by Brazil's government (being overwhelmed on the fourth).