Simultaneously smart and dumb, mixing clever satire with over-the-top raunchiness and unrelenting profanity, this equal-opportunity offender risks running off some of the very people who might appreciate it the most.
In his first turn at starring, directing and co-writing since the memorable Zoolander (2001), Stiller has taken as his target all things Hollywood, including the perfidy of producers and agents, and the self-involvement of actors who say things like "I don't read the script; the script reads me".
But because the world of contemporary show business, from the blood-letting of the slasher franchises to Britney Spears without underwear, is often so extreme, parody necessitates being even more excessive, leading, in this case, to a severed head and blood that spurts like Old Faithful, as well as language and situations that give new meaning and dimension to the notion of going too far.
Not only is Tropic Thunder guaranteed to offend, it already has.
One of the mock films it references, Simple Jack, and its story of a developmentally challenged young person who talks to animals, uses the tagline "Once upon a time . . . there was a retard".
This has so upset advocacy groups that a coalition of them is intending to call for a boycott to protest "the movie's open ridicule of the intellectually disabled".
But it would be regrettable if Tropic Thunder's undeniable excesses, including having an actor indulge in the 21st century version of blackface, blinded viewers to the reality that, like it or not, there is genuine humour and palpable satiric intent underneath the waves of unnerving bad taste and political incorrectness.
That comes not only from the script (written by the team of Justin Theroux and Stiller, and Etan Cohen) but from the film's committed and very funny actors, whose characters are presented in an especially clever way.
Because Tropic Thunder is the story of a group of thespians who come together to star in a Vietnam War action movie, Stiller chooses to introduce them with mock trailers from their last films, or, in the case of hip-hop star turned actor Alpa Chino (comic Brandon T. Jackson), with a salacious theatrical advertisement for his hot new energy drink, Booty Sweat.
After Alpa comes Tugg Speedman, played by Stiller.
Once the world's top action star, Speedman's Rambo-type action epics hit a wall with Scorcher VI: Global Meltdown, and an attempt at sensitivity in the aforementioned Simple Jack did not do too well either.
Jeff Portnoy (Jack Black) is also looking for a change of pace after playing, Eddie Murphy-style, all the members an entire brood of flatulence-obsessed behemoths ("America's favourite obese family") in The Fatties' and a sequel that can't be mentioned in a family newspaper.
At least not yet.
Then there is five-time Oscar winner Kirk Lazarus (Robert Downey jun), an Australian actor so committed to getting into character that he insisted on a "pigment alteration" operation to play the black soldier Lincoln Osiris.
In the trailer for Lazarus' last film, the controversial Satan's Alley, we see him going back in history to "a time when to be different was to be damned" and playing a monk passionately attracted to a fellow disciple played by Tobey Maguire.
As these trailers remind us, Stiller has a gift for take-no-prisoners sketch humour that goes back to his short-lived, Emmy-winning TV series The Ben Stiller Show.
Although it certainly has a plot, Tropic Thunder is best approached as a series of skits stretched out to feature length, a film easier to appreciate for its clever parts than for any kind of coherent whole.
These four actors, along with boyish newcomer Kevin Sandusky (Jay Baruchel), have gone on location in Vietnam to film the heroic memoirs of John "Four Leaf" Tayback, a gnarled veteran with prosthetic hands and a brooding presence (who else but Nick Nolte).
When director Damien Cockburn (Steve Coogan) starts to lose control of his high-powered actors, it is Four Leaf who suggests taking them out to the jungle and shooting the whole movie guerrilla-style until, in the director's memorable words, "you'll be begging for a body bag if it means a ride home".
But lurking in that jungle is a Vietnamese heroin-producing group run by the dread Flaming Dragon organisation and that ends up changing everything for the cast and its Hollywood support teams.
That includes Speedman's agent, Rick "the Pecker" Peck (Matthew McConaughey), and insane producer Lee Grossman (a completely unrecognisable Tom Cruise).
Like the actors stranded in the jungle, patrons of Tropic Thunder have to be ready for anything thrown at them by a film with a sensibility that makes the Three Stooges look like Faith, Hope and Charity. - Kenneth Turan
Tropic Thunder opens in theatres on Thursday.
