Donning high heels for a night out partying is the fashion equivalent of legal tender - the higher the heels, the richer you are and the faster a doorman lets you past the velvet rope.

But what if you decide to nix your Louboutins (don't we all own a pair?) in favor of more sensible footwear, like flats? Suddenly, your night out comes to a screeching halt.

High heels are a major part of nightclub culture because, aside from the sexiness factor, they help attract men with money. The law of the dance jungle goes like this: well-dressed sexy dames attract well-paying males, which elevates a club's popularity and status and - ultimately - its profits. Face it: in the club culture, women are looked at as pieces of meat on stilts - dancing shish kabobs.

When it comes to acknowledging the heel requirement, however, many establishments, particularly upscale Manhattan hotspots, keep mum about it. They'll never explicitly state, "Women must wear heels!" for fear of a discrimination lawsuit. Nightclubs know it would be the ultimate sexism to bar a female patron just because her soles are closer to the ground. Even posted dress codes stick to vague words like "smartly dressed."

All of this is a bit ironic since heels were originally created for men, not women. Dating back to 16th century Persia (now Iran), male horseback riders wore heels on their shoes to maintain balance while shooting arrows at their enemies.

The trend spread to Europe where noblemen wore heels to show status and to demonstrate machismo. The fanciful appearance of high heels set rich men apart from commoners.

"One of the best ways that status can be conveyed is through impracticality," Elizabeth Semmelhack, from the Canada-based Bata Shoe Museum, recently told the BBC. Women eventually adopted male fashion trends while men abandoned heels to a large extent. Once women began wearing them by the time the Enlightenment rolled in the 1700s, men decided heels were simply ridiculous.

Three hundred years later, heels are still looked upon as symbols of status even if nightclub officials won't admit it.

"These things aren't really explained that well," Lauren Menache, a representative from Jay-Z's upscale sports lounge 40/40 Club, said of the unspoken high heels code.

The sports bar, located in New York's Flatiron neighborhood, doesn't have an official dress code for the traditional Friday or Saturday nights out and doesn't require heels. Ladies and gents get in as long they are smartly dressed - with a few exceptions. There's that term again.

"We've turned girls away that don't look presentable," Menache said. "If she is wearing sneakers or flip-flops, that's definitely not going to fly."

But the right amount of fashion currency - a T-shirt, tight jeans and a pair of sky-high pumps - can buy any bouncer's yes vote.

At the Gansevoort Hotel in Manhattan's Meatpacking district, its rooftop Plunge Bar + Lounge follows a similar dress code. While rooftop manager Jimmy Turon says they do not require heels, it was all too obvious that a woman had been denied entry on a Saturday night in early July because her shoes - heel-less - were inappropriate.

"If you say that happens here, I don't know about that," said Turon referring to the incident, adding that not all sandals are acceptable, which means her shoes may not have been up to par.

The doorman never said the denial of entrance was because the woman wasn't wearing heels, but it is, after all, "at the doorman's discretion," Turon said.

The rule about wearing heels may indeed be unspoken, but managers are generally quick to admit that heels are good for business. They attract "ballers" - club-speak for men who race inside, ready to gush, swoon and spend big bucks to impress females parading around in platforms and sling-backs.

"Women are much classier in heels," said Turon, who personally believes women shouldn't be forced to adhere to the footwear rule. As a 10-year club industry veteran, he knows what any sensible club promoter covets the most. "They want tall people," Turon said. "They want tall women."

"It's status," said Menache, who also disagrees with having an established heel requirement.

"You want your clientele - on certain nights when they will be spending money - to look good." If a baller comes in wearing a three-piece suit, "You can't have a woman in there in sneakers," Menache said.

The same applies at the Plunge Bar + Lounge.

"We just want you to be presentable because we do have a higher clientele that we cater to," Turon said.

Nightclubs aren't the only ones that benefit from high heels; in terms of confidence building and simple pleasures, some women revel in the sheer joy of adorning their feet and attracting attention.

"I absolutely agree with them," said Jasmin Martinez, who can emphasize the point anytime she wants by flashing the stiletto-heeled shoe she had tattooed on the inside of her wrist. "If I spend as much time as I do with heels you can't come into the club with combat boots," she said during a recent Thursday happy hour at Copia NYC in Midtown.

It must be said, however, that walking in heels absolutely sucks.

"From a medical standpoint, they're dangerous," said Dr. Rebecca Pruthi, a podiatrist and director of Foot Care of Manhattan.

Heels can lead to a slew of medical issues, including blisters, inflammation of the foot tendons, ankle sprains and stress to the neck, shoulders and back, Pruthi said.

In extremely rare cases "you can develop spurs in your feet," meaning extra bone growth, said Pruthi, who also runs a blog for Dr. Oz. The same happened to heel connoisseur Sarah Jessica Parker, whose foot doctor once told her, "You've created that bone."

One '20s-themed restaurant and club named ProAbition in California actually tried enforcing a heel rule last year.

"Ladies: No flat shoes or sandals. Must have heels. Exception will be made if injured," reads an advertisement for its June 2013 grand opening, according to The Press-Enterprise.  

It wasn't long before the restaurant was forced to apologize and hastily reversed the dress code due to public outrage. 

"When it happens to you and you're turned away, it feels sexist," said Menache, who along with a group of friends was once turned away from a club in Miami for not wearing heels. "It feels like you're being ostracized as a woman."

She's right of course. But Menache also summed up the culture of shame that comes with being that one woman who shows up to dance wearing sensible flats amid a sea of gals in stunning stilettoes.

"It's like a scarlet letter," Menache said. "It's like painted on your chest."

Sure, but, as Hawthorne himself wrote: "If truth were everywhere to be shown, a scarlet letter would blaze forth on many a bosom!" That goes double for achy feet.