The Joker is an iconic villain. First introduced in the Spring of 1940, the Clown Prince of Crime has transformed from a violent criminal into a zany trickster and most everything in-between. He is vicious, strategic, and unpredictable all at once. This chaotic persona can seem beyond our understanding one moment and all too real the next. For the chaos and madness, though, the Joker has consistently proven a formidable archnemesis for the Batman as well as an entertaining figure to watch.

Part of what keeps the Joker fresh is the opportunity for interpretation. While the comics presented a mass criminal at first, they eventually softened into the more comical character fans of Cesar Romero might recognize. When the gags began taking a darker tone we saw a more intense take on the villain’s madness. The Joker of the Batman: The Animated Series and Tim Burton’s Batman offered a criminal who could match the seemingly unstoppable Batman. Better yet, stories to explore the relationship between the Batman and the Joker in a more philosophical sense. You could say this has been the best time to be a fan of the Joker.

All of this history informed the performance Heath Ledger delivered in The Dark Knight. The young actor paid homage to the zany, the dark, and the dastardly persona to create an entirely fresh and unforgettable take on the Joker. For all of the actor’s amazing work, there are aspects of the character some might have missed or passed over.

So now, 10 years after the initial release, we’re taking you back to 2008’s The Dark Knight with 25 Details About Heath Ledger’s Joker That Fans Choose To Ignore.

Master of Disguise

One of the lesser discussed characteristics unique to Heath Ledger’s Joker is a clear mastery of disguise. That’s especially impressive considering he sports a Glasgow smile.

Our first glimpse into this ability is during the opening scene. We have no idea the Joker is among the crew robbing the mob bank as they all wear collectible clown masks and plain clothes. Later, during the memorial, the Joker takes on the guise of an officer in the Gotham City Police Department deceiving the hundreds of cops surrounding him. Toward the end of the film, the Joker even dresses in a women’s nurse outfit to gain access to Harvey Dent’s hospital room (and it works).

Joker’s a Veteran (Maybe)

Okay, okay, you’ve probably heard this one buzzing around the web. Patton Oswalt brought particular fame to the fan theory that Heath Ledger’s Joker may be a traumatized war veteran. The theory cites references in the film such as the GCPD’s own guesses about the Joker’s origin, his unique skills in the movie, and his own references to battle.

They point to the way the Joker uses military hardware, like an RPG, with comfort and ease. For a supposed madman, he also weaves complex strategies for his crimes with tactics involving multiple moving pieces to achieve his goals. The way he handles an intense interrogation with Batman could even reveal professional training.

Well-Armed Joker

Whether or not the Heath Ledger’s Joker served, we can all agree that he is exceptionally well-armed. That point is easy to overlook, too. Throughout The Dark Knight series, the Batman story is given roots in our modern world including our anxieties about war, politics, and social structure. This cultural context means the Batman doesn’t just have some interesting gadgets – he’s equipped with a variety of military-grade armaments often times more advanced than those used in the war.

If the Batman resembles an advanced soldier, then the Joker is more like a well-armed enemy of one. The Joker’s armory includes shotguns, pistols, machine guns, rocket launchers, knives, and even plastic explosives.

The Joker Knows People

The Joker is dark and unhinged, but he also understands people. Just look at his achievements. Even before the bank heist, he’s able to convince a crew to rob a bank owned by Sal Maroni – the biggest mob boss in Gotham City. He manipulates the anxieties of the mob bosses concerning the Batman to force them to hire him, which empowers the Joker even more.

Finally, the Joker orchestrates the transformation of District Attorney Harvey Dent into a man so broken that he holds a child at gunpoint for reasons even Dent doesn’t seem to totally understand. The only person the Joker doesn’t seem to understand is Batman.

Who Needs Gas?

One thing Heath Ledger’s Joker didn’t include is his signature weapon – laughing gas. Depicted in Batman: The Animated Series, Tim Burton’s Batman series, and even the on-going show Gotham, this gas is usually capable of turning everyday citizens into ever-smiling zombies who often laugh themselves into an early grave.

However, this Joker doesn’t abandon everything about the gas. From picking off the city’s leadership to holding hundreds hostage with bombs, the Joker coordinates massive criminal threats and moral challenges to achieve the same ends – that is, making others like him. Where laughing gas often changed people to resemble the Joker physically, his actions in the film instead seek to change their thinking.

The Joker is Temptation

We might think of the Joker as an agent of chaos, but he could just as easily be called an agent of temptation. The Joker simply doesn’t seem capable of leaving any rule alone. This clear is enough in his criminal behavior but becomes more interesting when the rule defines another character.

When the Joker believes Harvey Dent is the Batman, his torments challenge the so-called “White Knight of Gotham” to abandon his beliefs and take the law into his own hands. While the Joker is beaten during his interrogation, he can’t stop himself from challenging the Batman to break his no-killing rule. Maybe he’s committed or maybe it’s a compulsion.

Feared By Fans

Today the performance by Heath Ledger is lauded as one of, if not the best, performances of the character. Many imagine what might have come next had the actor lived long enough to see his success firsthand and reprise his role in The Dark Knight Rises. Sadly, that wasn’t to be.

What many forget is that Heath Ledger was considered a risky move. Christopher Nolan considered Ledger the best fit for the role, but fans weren’t convinced. The young actor had his successes in romance and comedy, which concerned many that such a dramatic role was a poor fit. Even Jack Nicholson was irritated about his run as the Clown Prince coming to an end.

The Glasgow Smile

One of the most iconic aspects of Heath Ledger’s Joker was, of course, the smile. Flaking dried makeup looked offputting, but mercifully, it hid the cringeworthy scars rising from the corners of his mouth. Or at least, the makeup made the sight a little less bad. It’s really a testament to the makeup artist (who was awarded for his work, by the way).

What some don’t realize is the fact these scars are based in reality. It’s called a Glasgow smile. The name is said to come from Scotland where especially brutal gangs would leave those unfortunate enough to earn their ire with this life-long wound. Really makes the Joker that much scarier, doesn’t it?

Fully Invested

Heath Ledger said that Christopher Nolan showed him the world of The Dark Knight. That’s what excited him most. This was a complex role requiring serious dedication, research, and the willingness to dip his toe into a strange way of being. To achieve this, Heath Ledger isolated himself for a month in a hotel room.

While there, the actor practiced and studied, keeping a journal now known as the “Joker Diary” with his thoughts and inspirations. Ledger based his mannerisms and look on a variety of sources including laughing hyenas and A Clockwork Orange’s Alex DeLarge – even replicating that “Kubrick Stare” during the interrogation scene.

The Tongue Thing

The Joker is expected to be eccentric. Wild gestures, questionable fashion, and the bone-chilling laugh are a few of the staples. One unique contribution from The Dark Knight was the “tongue thing”. You know, the way the Joker licked at the corners of his mouth, sometimes even pausing his story to do so.

It’s a small gesture, but an important way to make the character all the more real. According to Christopher Nolan, the “tongue thing” started when Heath Ledger’s prosthetic refused to stay in place. Ledger used his tongue to fix it while talking. Even after that little mishap was fixed, the actor kept the gesture as it seemed to fit the Joker.

A Little Too Real

Remember sitting at the edge of your seat as the Batman came face-to-face with the Joker? The entire film teased us about the confrontation, pulling us all around the city until finally, these extraordinary figures crossed paths in an intentionally dull interrogation room. It seemed this would be a battle of the minds.

Then the Batman slams the Joker’s head against a window. Part of what made this scene so real is that Heath Ledger insisted on making the fight real. He egged Christian Bale on to actually hit him. When Bale refused, Ledger threw himself around the room.

The Voice(s)

A number of references informed the character Heath Ledger brought to life. Interestingly, one of the inspirations Ledger shared with Christopher Nolan was that of the ventriloquist dummy. Ledger borrowed the many of the body movements and the surprising range of sound from the dummies when playing the Joker.

Looking back, the reference is clear from the way the Joker constantly hunches over or in the mob boss scene when he reveals the grenades lining his jacket. His body moves as if he’s not in control, only adding to the sense of chaos. What completes this performance is the voice, which even proved surprising for Nolan.

Why So Serious?

The Joker has a defined look and laugh. While incarnation brought to life by Cesar Romero may seem worlds away from Jared Leto’s latest take, in a way, both follow the same set of rules. The pale skin, red lips, and green hair are constants. What The Dark Knight gave us was a catchphrase.

Why so serious? It all started with a marketing campaign gone viral. Full of cryptic messages and spanning over 75 countries, the campaign compelled people to effectively enlist in the Joker’s following to learn more. Not only was it a spectacular success, but the campaign also left us with a meme 10 years old and still going strong.

True To His Roots

There is no question that Christopher Nolan brought a gritty vision to the Batman universe. For every battle with henchmen, Bruce Wayne seems to earn a new scar. If anybody was expecting Heath Ledger to go comical for his take on the Joker they weren’t paying attention. Still, the Joker was uniquely disturbing.

The Joker leaves a trail of bodies in his wake, including Gotham’s leaders as well as his own henchmen. This take might not be as divergent as some think, though. When the Joker was introduced back in the 1940s his deeds often included the worst kind of criminal activities. In a way, this was a return to his roots.

Daddy Issues

The Glasglow smile, makeup, and chaotic mannerisms all prevent us from ever seeing the man behind the villain. While Gotham seems to breed this kind of theatrics, the Joker works especially hard to not be understood. He constantly tells the story of how he got his scars – often as a way to create fear – and each time that story is different.

Even the Gotham City Police fail to get further than three wildly different theories about his past. Curiously, the Joker repeats points about his father. Once as an abuser who ultimately cut his mother and him, then again simply to say he hated the man. It’s a rare insight into the man behind the smile.

But First, Shopping

When we’re first introduced to the Joker he seems to be another henchman robbing a mob bank. A clown mask, a dusty blazer, and a white button-up. It’s all rather forgettable.

The next time we see the Joker is during the meeting between Gotham’s mob bosses. He’s wearing his signature purple and green three-piece suit, which a mobster calls cheap. The Joker promptly corrects him, saying the suit was actually quite expensive and paid for with the stolen money. Although brief, these scenes suggest the Joker took the stolen money and almost immediately visited the local tailor for some new clothes. Not quite the Joker’s sports car in Suicide Squad, but still good.

The Joker is a Hitman

If we asked you what the Joker did for work, what would you say? Okay, besides rob banks. Most comic book characters aren’t weighed down by the pressures of real life. Every hero seems to have a slush fund. Every villain assumably pays for their dastardly hijinks with illegal schemes accomplished off-screen.

The Dark Knight breaks that cliché. The Joker is hired by Gotham’s mob bosses Sal Maroni and the Chechen to end the Batman after the mob’s accountant is taken down in Hong Kong. In other words, the Joker is hired on as a contracted criminal for the mob. This conveniently explains the steady stream of henchman, weaponry, and vehicles, too.

He Sort of Makes Batman a villain

Taking out the Batman is easier if you know the man behind the cowl. This becomes the Joker’s first order of business after he accepts the contract from Sal Maroni and the Chechen. The Joker quickly abducts and kills a Batman imposter while recording the entire horrific affair. There’s a threat too: the Batman must reveal himself or more will be eliminated.

Bruce Wayne is torn by this decision, but his inaction leads to the passings of the commissioner and a judge.  Considering ample opportunity to prevent the events that are to happen and absolutely no reason to think the Joker was bluffing, that puts some blame on the Bat.

The Joker Finds Purpose in Batman

The Dark Knight often uses the Batman and the Joker to pose existential questions about morality real. Yet, both characters initially seem unconvinced. Bruce Wayne expresses doubt in his role with both Alfred and Harvey Dent. The Joker is merely keeping himself busy with small-time heists.

Neither character comes to life until they meet in the interrogation room. They challenge each other, the Batman with barely restrained violence and the Joker with infuriating mind games. In this scene, they both realize they’ve met their match.

A Mad Detective

There’s more than chaos and anarchy to this Joker. He’s calculating, strategic. The Joker tries to egg the Batman into revealing his identity by eliminating Gotham officials. These targets also have a connection to a specific man the Joker suspects hides behind the cowl – Harvey Dent. Despite being wrong, the Joker’s plan still breaks Dent after Rachel is involved.

The Joker realizes his mistake during the interrogation. He also seems to draw another conclusion, noticing that Rachel bothers the Batman. He asks, “Does Harvey know about you and his little bunny?” This question aligns well with Bruce Wayne, who is in love with Rachel, suggesting the Joker may have concluded the Batman’s true identity.