Writer/director Brian Helgeland, who won an Oscar for the "L.A. Confidential" screenplay, takes the story of a young man pretending to be a knight and plays fast and loose with the particulars. Although it is set in the 14th century, the characters talk like 21st century folks. The Nike logo turns up on a suit of armor. A princess wears a variety of attractive, but bizarre, outfits that do not fit the time period, including one number that looks like something Audrey Hepburn wore in "Breakfast at Tiffany's." As if all that wasn't enough, the orchestral score is spiced with a number of classic rock songs, from Queen's "We Will Rock You" to War's "Low Rider." Purists are already howling about the movie, of course, but who cares? What Helgeland does here is fun.

A side note: One critic accuses the filmmaker of using the rock chestnuts to "woo the youth market." Pardon me, but does this guy really think that kids who listen to current pop music are going to embrace a production because its soundtrack includes "Taking Care of Business" and "The Boys are Back in Town?" Give me a break. The paying audience at the sneak I attended Saturday were mostly couples ranging from adult to late middle age.

The frills in "A Knight's Tale" may be from left field, but the story is strictly (in fact, overly) traditional. William (Heath Ledger from "The Patriot") is squire to Sir Ector, a jousting legend who dies at the beginning of the film. Desperate for money, the young man convinces fellow squires Roland (Mark Addy) and Wat (Alan Tudyk) to assist him as he furtively dons the knight's armor to compete in his place. The facade is successful and William decides to work towards the world championships, despite the fact that peasants are not allowed to participate.

Luckily, the boys run into the one and only Geoff Chaucer (Paul Bettany) staggering naked down the dirt path. Years away from his Canterbury days, the unemployed writer and chronic gambler joins them and forges a fine set of identification papers. William becomes Sir Ulrich von Lichtenstein of Gelderland, jouster extraordinaire, with Chaucer providing florid intro speeches that would make a WWF wrestler tear up with joy. A fiery blacksmith named Kate (Laura Fraser) soon joins the gang as they head from stadium to stadium, with rapturous crowds chanting Ulrich's name.

William is enraptured as well, by the beautiful, hauty Jocelyn (Shannyn Sossamon). While he tries to win the heart of the fair maiden, an enemy glowers from the sidelines. Sir Adhemar (Rufus Sewell from "Dark City") detests the young upstart and makes clear his intentions to retain his jousting title and to snatch Jocelyn while he is at it.

Helgeland brought his cast together in Prague a month before shooting began to practice jousting and get to know each other. The actors spent their days rehearsing and their nights drinking. By the end of their prep time they were thick as thieves and the results show up onscreen. The relaxed bond between the actors/characters makes the film work, even when the dialogue is weak. Mark Addy ("The Full Monty") and Alan Tudyk make a particularly likable team, with Addy bouncing caustic one-liners off Tudyk's chronic blustering. Paul Bettany is an absolute hoot as Chaucer, with Laura Fraser's down to earth performance anchoring the group.

The best segment in the film shows off the talents of the three lead players. A formal dance begins with harpsichord music and turns into a joyous contemporary romp set to David Bowie's "Golden Years." Heath Ledger is dashing and charismatic, with his unforced masculinity filling the screen. Newcomer Shannyn Sossamon projects erotic elegance as she puts her dance training to good use. The two serve as a delightful center to a magical scene. While they strut their stuff, Rufus Sewell does some remarkably subtle acting. Watch his face as he makes the transitions from arrogance to anger to confusion to sadness to defeat, all without a single word.

The playful, frothy moments of "A Knight's Tale" shine, while the latter part of the film suffers from an attack of mawkishness, finally turning into a medieval "Rocky." Brian Helgeland needs more discipline as a director. At two hours and eight minutes, his movie screams for editing. I'd have cut some of the jousting scenes, which are numbingly repetitive. I also would have rewritten the entire third act and deep-sixed the pathos. But the bottom line is that Helgeland's incongruous flourishes and top-notch ensemble cast save the film from its many, many problem areas.