Let's be clear about one thing upfront: Ninja were (and, depending on who you ask, still are) a real thing. During the feudal era in Japan (largely beginning in the 15th Century), many isolated rural clans were resistant and even hostile to the idea of being ruled over by the laws of nobles — especially when they were being enforced by often oppressive samurai. Unable to stand up in traditional combat to the expensively funded and heavily-outfitted samurai, some of these resistant clans developed unique martial-arts techniques and fighting strategies based on mastery of one's environment, along with weapons based on common tools and simple farming equipment, in order to even the playing field in combat.

The field was "evened" so effectively, in fact, that the nobles began to hire the best of these clans' so-called "ninjas" as spies and mercenaries. They became highly sought-after for their skills and willingness to do "dirty work" that samurai often felt was beneath them. Two such clans, the Koga and the Iga, became so well known for producing skilled ninjas that some would leave their communities to become professional operatives for specific nobles or the Shogunate itself. Some even managed to establish "respectable" houses/lineages of their own, eventually becoming the basis for the "shadow warrior" archetype by which ninja are popularly imagined today.

As befits professional killers paid to undertake what would today be called "black ops" missions, little is recorded of actual ninja activity in Japanese history. Rather, the world mainly came to know of them through Chinese historical-fiction (the word "ninja" itself is an Early Middle Chinese translation of the kanji 忍者; which is read as "shinobi" in Japanese), where ninja were popularized as an example of treacherous, dishonorable behavior to be expected of Japanese villains. This, of course, made them a popular villain for the originally Chinese-centric martial-arts film genre as well. And when so-called "kung-fu movies" exploded in popularity worldwide in the '70s and '80s, the ninja legend exploded right along with it.

Here are the 15 best movies that came about as a result.

15. THE KILLER ELITE (1975)

Sam Peckinpah? one of the greatest action filmmakers of all time, made a ninja movie?! With James Caan, Robert Duvall and Burt Young??!! For action junkies it sounds too good to be true... and unfortunately it is. This fairly by-the-numbers thriller about a team of veteran mercenaries protecting a Japanese diplomat doesn't rate as one of the legendary tough-guy director's best, and isn't a particularly enthralling ninja feature, but it's a solid movie and a landmark for ninja fans as one of the first mainstream American feature films to give the shadow-assassins a "realistic" presentation — albeit one confined mostly to the extended shipyard-brawl finale.

Viewed today it's more of a curiosity item, a chance for martial-arts fans to see ninja presented in Peckinpah's more "grounded" Western style (no wirework, no exaggerate sound-effects, no invincibility to gunfire), though some may be disappointed to discover that when Killer Elite's ninja do finally make their appearance, they don't exactly rate the proper respect from the main (Western) cast. Instead, the film treats them more as a deadly (but hardly terrifying) part of the Japanese characters' strange/"exotic" cultural quirks. Regardless, at the time, seeing kung-fu/grindhouse fixture like ninja sharing the screen with major Hollywood stars was something entirely new and exciting.

14. NINJA FANTASY (1987)

Nobody did more to make ninja a fixture of video store shelves in the '80s (but also targets of ridicule and parody) than enigmatic Hong Kong producer/director Godfrey Ho, believed to have been behind over 80 films between 1980 and 1990 under a litany of assumed names, including Godfrey Hall, Benny Ho, Ho Chi-Mou, Ed Woo, Stanley Chan, Ho Fong and more. Nearly all of his films featured the word "Ninja" somewhere in the title and were created by editing newly-shot fight scenes featuring colorfully-costumed ninja into (unrelated) pre-existing low-budget films from Thailand, the Philippines, and elsewhere in Asia, and then using English-language dubbing to (loosely) tie the scenes together with an entirely new plot.

Ho films are often interchangeable, but Ninja Fantasy (also released as Twinkle Ninja Fantasy and Empire of The Ninjas) remains one of his more easily-identifiable and well-known efforts — particularly thanks to an infamous sequence wherein a blue-clad ninja battles a swarm of red-suited attackers who sneak up on him and his lady friend on a secluded beach by transforming into fish. Ho may have been a master cynic, a gonzo outsider-artist, or both, but his bizarre fight scenes have an unmistakable energy to them, and his signature penchant for Skittles-colored ninja costuming has influenced everything from Teenage Mutant Ninja Turtles to Mortal Kombat.

13. THE OCTAGON (1980)

Here it is: The only remotely good movie starring Chuck Norris where the future Walker: Texas Ranger star and Bowflex pitchman isn't getting smacked around The Colosseum by Bruce Lee. Given that he transitioned almost immediately away from martial-arts films to gunplay-heavy fare once the Rambo-imitator era hit, it's easy to forget just how novel Norris' original appeal as a white American action hero with the moves of an Asian kung-fu star seemed to audiences of the late-'70s - and The Octagon serves as a fitting reminder while also being (almost) a good movie in its own right.

The soon-to-be Karate Kommando stars as a ninjutsu-trained former karate champ conscripted to help fight a terrorist cell that turns out to be a ninja clan whose ranks include his Japanese ninja "blood brother" (Tadashi Yamashita) and can only be infiltrated by surviving a deadly obstacle course called "The Octagon." Generic plot aside, it's a thoroughly entertaining actioner with excellent ninja scenes, often credited with kicking off the "ninja craze" in low-budget '80s action cinema.

12. SHINOBI: HEART UNDER BLADE (2005)

Believe it or not, Japanese pop-culture remains less consistently fascinated with ninja than the West, and especially neighboring China, but the subject enjoys intermittent bouts of public fascination, particularly in the realm of manga, anime, and historical-fantasy novels. Shinobi: Heart Under Blade is an adaptation of one such novel, Futaro Yamada's The Koga Ninja Scrolls, a fictionalized dramatization of a feud between the Koga and Iga clans at the dawn of the Tokugawa Shogunate that also served as the basis for the anime series Basilisk.

The story? It's Romeo & Juliet with ninjas: The male and female heirs to the Koga and Iga leadership are plotting to hook up and unify their clans, an event that Shogun Tokugawa Ieyasu believes could create an army powerful enough to challenge his rule because of a prevalence of superhuman ninja abilities in both clans. To prevent this, his forces covertly stir up hostilities between the rival villages while he orders a five-on-five battle to the death between each clan's best fighters. It's all very melodramatic and tragic, while also sanding some of the stranger edges off the novel (where the ninja couple's romance is also a plan to mix their bloodlines in order to reduce the inbreeding that created their clan's super-powers but also resulted in rampant deformities) but it commits whole-hog to its operatic aesthetic and features endlessly-inventive fight scenes.

11. NINJA TERMINATOR (1985)

The aforementioned Godfrey Ho has at least 115 known films to his credit, so don't be too surprised to see him turn up on this list twice. Ninja Terminator is often regarded as Ho's "best" ninja movie and is certainly the most quintessential, as it features some of the best action (thanks largely to underused martial arts actor Richard Lam) the most coherent storyline (a quest to collect three pieces of a gold statue said to grant ultimate ninja power) and the presence of B-movie star Richard Harrison — often thought of as "the" Godfrey Ho ninja actor.

Harrison, a veteran of the gladiator and "spaghetti western" genres who once joked that his "greatest contribution to cinema" was turning down A Fistful of Dollars and recommending Clint Eastwood for the role instead, was paid to shoot what he thought was a small number of ninja movies for Ho while working in Hong Kong. Only discovering later that, through Ho's cut-and-paste editing, he had "starred" in over a dozen Z-grade ninja movies, which would later be said to have ruined his reputation as an actor but are today amongst his most widely-known work.

10. PRAY FOR DEATH (1985)

When low-budget ninja movies were at peak popularity in the U.S., Japanese actor and martial-artist Sho Kosugi shot to B-movie stardom on the basis of memorable appearances in Canon Films' so-called "Ninja Trilogy" (Enter The Ninja, Revenge of The Ninja and Ninja III: The Domination) and being a "real-life" ninja...in as much as he's reputed to have extensively studied ninjutsu along with Karate (Shindō jinen-ryū school), Kendo, Judo, Iaido, Kobudo and Aikido. He also had onscreen charisma to spare, and got to demonstrate it in Pray For Death — one of the rare American martial-arts films of the era that placed Asian characters at the center of their own story.

The plot is fairly boilerplate, with Kosugi set as a Japanese family man who moves his family to the U.S. so that his American-born wife can open a restaurant. He is then forced to break out his (secret) ninja skills to defend said family from corrupt cops and local crime lords. Simple stuff, but the action is immensely satisfying, and it's commendable to see a Japanese immigrant family as the unambiguous heroes of a movie made in an era when anti-Japanese xenophobia was running high in the United States.

9. MIRAI NINJA (aka CYBER NINJA) (1988)

Keita Amemiya, the director/fantasy-artist/FX-supervisor/designer sometimes called "the H.R. Giger of Japan," is best known for directing and character-design duties on various Kamen Rider and Super Sentai (aka Power Rangers) series. Amemiya first made his name with this bizarre theatrical sci-fi feature intended to launch a franchise for Namco. Centered on a future soldier transformed into a half-machine ninja in order to battle an invasion by cyborgs from another dimension, it's light on plot but heavy on ninja action and creative low-tech FX, though its main lasting contribution to the broader popular culture was a semi-popular arcade game never released outside of Japan.

Amemiya would later find greater success as the director of Zeiram and Mechanical Violator Hakaider.

8. NINJA III: THE DOMINATION (1984)

Canon Films followed their moneymaking B-grade ninja hits Enter The Ninja and Revenge of The Ninja with this third "spiritual sequel" in a series unified only by the presence of Sho Kosugi in (unrelated) ing roles. This is the strangest of the three, and therefore widely considered to be the "best" of the lot.

A bizarre mash-up of ninja and exorcist movie tropes, the plot concerns a woman who becomes possessed by the spirit of a dead ninja, which forces her to commit martial-arts murders against her will. James Hong tries to help as a Chinese exorcist, but the task of setting things right ultimately falls to Kosugi, as a good ninja who can expel the evil through a ritual fair duel. There's nothing else quite like it, even in the ninja genre.

7. 007: YOU ONLY LIVE TWICE (1967)

One of the all-time great ninja-centric action movies and easily one of the best original James Bond films...if you can manage to look past all the incredibly uncomfortable (even by James Bond standards) racism — which is easier said than done in a film whose central plot element is that Sean Connery can "become Japanese" with some skin-darkening makeup and black hair dye. Yeesh.

Too bad, since it features the best Bond (Connery), the best Bond villain (Donald Pleasance as Ernst Stavro Blofeld), the best Bond villain lair (a rocket-launch base hidden inside a hollowed-out volcano) and the best Bond finale action sequence; with 007 leading an army of ninja to storm the volcano base. It even has one of the sharpest screenplays of the Connery era, thanks to Roald Dahl (really!) on adaptation duties. Too bad the film's second act (built around the "Japanified" Bond) is so profoundly uncomfortable.

6. TEENAGE MUTANT NINJA TURTLES (1989) 

Whatever the other merits of the myriad of Daredevil run) that started the franchise but render the titular Turtles themselves in the fashion of their more strongly-characterized animated series incarnations.

The result is a shockingly-compelling action movie that feels like it has real stakes and a surprising amount of heart (what "kids movie" today would slow down for the meditative 2nd act sojourn to the farm?) built around a set of genuinely thrilling ninja battles that were way more intense than kids weaned on the slapstick-heavy cartoon were expecting. The results blew the minds of a generation...and outraged enough parents that the Turtles were forced to not use their weapons in the sequel. Bogus.