Rack your brains for an archetypal American rite of passage and you might come up with the high school prom or a baseball game - standard fare in Hollywood coming-of-age movies. But not all American school rituals celebrate beauty or brawn. The chances are that during their formative years most Americans will have nervously trooped to the front of class to spell out words barked out by their teacher.

Spelling competitions, dubbed “bees” (no one is quite sure why, although a “bee” refers to a community social gathering of friends and neighbours), are a national institution. Every year, a staggering 10 million students spanning 93 per cent of school districts, pit their spelling skills against each other word-for-word in gladiatorial cerebral combat.

More august than American football’s Super Bowl, the 78-year old National Spelling Bee showdown in Washington DC, where the cream of the United States’ young spellers square off, is televised live on the sports channel ESPN, home to baseball’s World Series and basketball’s NBA finals .

The national bee was conceived in 1925, a quaint 1930s brochure relates, as a “beneficial stimulant to the study of spelling”, which was “a dull subject”. An attendant benefit was the “promotion of civic consciousness by pitting the champion of one community against the champions of others”.

Back then, finalists were accorded an audience with the president. Such honours may be long gone, but the bee’s popularity remains undented by the advent of computer spellcheckers. The last speller left standing in the modern sudden-death competition scoops $12,000 (pound;7,538), an Encyclopaedia Britannica box set, a trophy that wouldn’t look out of place at Wembley, and formidable school bragging rights.

Passions run high: in 1999, the event was almost engulfed by a diplomatic incident when Jamaican entrants were barred after it was discovered that the organisers of the island’s heats had failed to adhere to official guidelines. Amid a storm of protest, the Jamaican embassy in the US registered an official complaint, and the former vice-presidential candidate and civil rights leader Jesse Jackson weighed in on behalf of the Caribbean contingent. The dispute has since been resolved, and in this year’s final Jamaica’s finest took their place alongside prodigies from Mexico, Guam, Puerto Rico, the US Virgin Islands, the Bahamas, American Samoa and the United States mainland.

International controversy or not, the Washington final is never short on drama as 250 or so youngsters aged from eight to 15 file onstage to duke it out against Merriam-Webster’s Third New International Dictionary - all 460,000-odd words (the average computer spellchecker contains a paltry 50,000). A sampling from a recent final included “porraceous” (clear green light), “morigeration” (servile obedience) and “repoussage” (hammering out thin metal). Some competitors show no nerves; impassive and self-assured, they reel off spellings. Others squirm in the spotlight, contorting their faces as they retrieve the letters from the recesses of their mind, or cast their eyes skyward for inspiration. Still others freeze, gripped by panic.

Spellers trudge off, scolding themselves after stumbling on a sitter, or punch the air after winging it on an unfamiliar word.

In the audience, anxious parents knead worry beads, clasp their hands in prayer or enunciate letters in unison with their child. All the while, a hushed commentator narrates proceedings. He wouldn’t be out of place at a snooker match.

Such was the spectacle that planted the seed for Spellbound, a film on the bee phenomenon. It has played to packed houses and garnered rave reviews in the US (narrowly missing this year’s Oscar for best documentary) and opens in the UK next month.

“There’s a sense of magic about it. You can’t understand how these kids can spell words that most people 30 years their senior couldn’t,” says director Jeff Blitz. But it is the lurking subtext that interests him more. “The competition seems to be this blank slate; all these kids and their parents project so much meaning on to it. It’s a great empty vessel that gets filled up with dreams.”

Still, on paper at least, a documentary about spelling doesn’t seem the stuff of a hit movie, and Blitz recalls the tough sell to his collaborator, Sean Welch. “I was not convinced that a documentary about spelling would be that interesting,” recalls Welch. That changed after six months’ mulling over the project when he visited Blitz’s home. “On the wall were computer printouts of the spellers he’d been researching, including biographies, and a map with Post-it notes and pins showing where they lived. He sat me down and explained the mosaic of stories, and how he wanted Spellbound to use the spelling bee as a backdrop for a film about the celebration of education, families, the human spirit and the American dream.” Welch was sold.

Spellbound tracks eight hopefuls in the 1999 competition, cutting a swath across the US like a classic road trip from the mansions of Connecticut (the US’s closest thing to the Home Counties) to the big-sky country of north Texas; from inner-city Washington DC to a redneck Missouri trailer park.

The saga of the film’s production is every bit as heroic as the struggles of the precocious spellers. The shoestring budget was met from the pair’s own pockets, using scrimped air miles to criss-cross the US following the families. Blitz and Welch have yet to tot up the damage, but they “max-ed out 14 credit cards”, says Welch. “If anyone had told us how long it would take or how expensive it would be, we’d have thought twice.” Setbacks included a family who got cold feet, forcing them to scrap hours of footage; another fancied competitor they’d filmed dropped a syllable in “monotonous” and bombed out of his state heat.

But there were successes. Emily Stagg from Connecticut snatches spelling revision between equestrian lessons. April DeGideo crams up to nine hours a day. Her father, a bartender, confesses his life hasn’t been easy, but April hopes to buck the odds. African-American Ashley White, the eldest child of a one-parent family living in a grim Washington DC tenement, carries the hopes of her jailed uncles into the national final.

And for Angela Arenivar from Perrytown, Texas, the daughter of non-English speaking Mexican immigrants, qualifying for the final represents a consummation of the American dream. It gives her, she says, the chance to meet like-minded peers and not feel like the odd one out. “When you excel at something it makes you an outsider. That’s how I felt sometimes with my spelling because it wasn’t the cool thing to do in my town,” says Angela, now 18 (she was 14 when the film was made).

To get there, Angela faces an epic nailbiting play-off with a local rival that runs to 54 rounds before her opponent fluffs “cabana” and she nails “crocodilian”. To train, Angela devised crossword puzzles, formed words with alphabet cereal, even chalked letters on the pavement outside her home to memorise words.

There were no such homespun methods for Neil Kadakia of chi-chi San Clemente, California. His father drills him on words culled from previous competitions, deploys a cadre of coaches and harnesses computer programs.

And just in case perspiration doesn’t work, he invokes divine inspiration, enlisting people in his native India to pray for Neil.

Who wins? We’re not telling, except to say it’s a girl who says it was the “most drastically life-changing event I’ve gone through”. She rubbed shoulders with luminaries such as the lunar astronaut John Glenn, basketball hero Michael Jordan and Nobel laureate author Saul Bellow. And she was pictured in Time and Newsweek. But fame has its downside, she’s found. “The pressure to excel in other parts of my life increased dramatically - living up to that is daunting. On the first day of high school, I went into my English class and everyone expected me to get top grades.”

Blitz and Welch have discovered that good spellers aren’t necessarily wordsmiths. Rather than lawyers or teachers, the highest proportion of bee champions go on to become doctors; one in four former national winners is a medic. “It’s about the ability to memorise words, aligned to all the facts that need to be memorised in medicine, and not being intimidated by massive workloads,” says Blitz.

Paige Kimble, national bee director and a former champion, says it’s only part of the story. “There are lots of good spellers, but it’s another thing to stand in front of cameras with photographers clicking, compose yourself and think how to spell a word you’ve never heard of.”

Spellbound is released on October 10. More details at www.spellboundmovie.com