This month marks the 20th anniversary of the NC-17 rating, invented by the MPAA to separate certain graphic yet non-pornographic films from the seedy connotations of the X rating. But the new classification immediately had its own stigma and many theater chains and video stores wouldn't carry films with the NC-17 mark. So then some films that didn't want to cut content to receive an R rating went out to cinemas unrated. Unfortunately, many chains were also unwelcome to circumvention of the MPAA. Now AMC Theatres, which has long been one of those against booking films lacking classification, is opening its screens (around 60 locations) to the horror sequel 'Hatchet II,' which makes this the widest opening for an unrated film in 25 years.

Of course this decision comes via the accessible horror genre rather than through something more "adult" or sex-centric like a Todd Solondz, John Waters or Harmony Korine, or even an Adrian Lyne or Paul Verhoeven. But will the erotic stuff be treated as fairly as the violent and gory? It's assumed that following the October 1 release of 'Hatchet II,' the also-unrated horror release 'I Spit on Your Grave' will be booked in similar fashion. Then what? If the first title is successful -- and I think it has a good shot at being the highest-grossing unrated film of all time -- can we expect filmmakers to actually start trying to garner an NC-17 just to then go out unrated? Will films that wouldn't even receive an NC-17 exploit the sudden approval by going unrated anyway? It could get as bad as the present situation with unrated DVD editions, which are rarely worth their ironic marketing gimmick.

After the jump lets look at some of the more notable films that were distributed unrated and see how they performed.

'The Evil Dead'- I'm not sure if this 1983 film is what AMC is referring to in claiming its been 25 years since an unrated title has been released this wide, but Sam Raimi's original 'Evil Dead' did go out to 128 theaters and took home more than $2 million (as far as I know from that initial run).

'The Passion Recut' - After racking up more than $350 million in wide release, breaking the box office record for independent film and becoming one of the highest-grossing R-rated films ever, Mel Gibson's 'Passion of the Christ' was re-released in a new form that went out unrated. The interesting thing is that it featured less graphic violence than the original cut. Due to the lack of rating, I assumed the re-release was gorier. It grossed an extra half a million.

'Happiness' - Todd Solondz and distributor Good Machine released this indie classic unrated after receiving an NC-17 from the MPAA. It seems back then there was less of a problem with the lack of classification compared to the stigma of NC-17 and the film went as wide as 60 screens and took in nearly $3 million. Since then Solondz has gone with mixed attempts. 'Storytelling' ($900,000 gross) ended up with an R after a statement-making bit of self-censorship but then 'Palindromes' ($553,000 gross) went out unrated. His latest, 'Life During Wartime' ($269,000), is rated R.

'Requiem for a Dream'- Many of us didn't discover Darren Aronofsky's stylish junkie drama until video, when the film was given an R-rated re-cut with less footage of the disturbing orgy sequence. But given that its theatrical run was without a rating, it's remarkable that it did ultimately end up on more than 90 screens and earned a decent domestic gross of $3.6 million.

'Antichrist' - There was no way Lars von Trier's film could have been cut down for an R and been the same film, but its shocking, graphic content could have been used to its advantage in wide release were it allowed to go to the multiplexes. Actually, that's probably not true. People don't go out to be stunned the way they did when 'The Crying Game' was released in the early '90s. Plus, 'Antichrist' was available through cable VOD for those who wanted to see what the fuss was about. Theatrically it only made $400,000.

'The Brown Bunny' - Similar situation to 'Antichrist,' though more blatantly hardcore with its sex scenes (specifically the infamous fellatio bit between Vincent Gallo and Chloe Sevigny). This came before such films made up for lack of screens with VOD platforms. Domestic gross: $366,000.

'Che'- Steven Soderbergh's film also had the benefit of IFC's VOD service with which to reach most corners of the U.S. non-theatrically. Still, for a film longer than four hours and much of it subtitled, the unratd full version of 'Che' did significant business on nearly 40 screens: $1.5 million.

'Valhalla Rising' - Nicolas Winding Refn's recently released follow-up to his highly acclaimed 'Bronson' has a lot of appeal for fans of violent action and horror films. And it received mostly positive reviews, too. Again, though, it's an IFC title so it's hard to tell if they might have sought a wider release had it not had the VOD supplement. Domestic gross from 2 screens: $31,000.

'Zyzzyx Road' - Would a rating have helped this Katherine Heigl film gross more than $20 (not counting the tickets bought by crew members later reimbursed)? Nah, it probably would have still been dumped to a single Dallas cinema and had a similar fate.

'A Film Unfinished'- Beastie Boy Adam Yauch recently had a fit regarding the MPAA's decision to stamp this Holocaust documentary with an NC-17 rating. It ended up being released unrated, which will apparently help it get into school programs. But few docs, let alone historical record films such as this, end up in many AMC locations anyway. Regardless of its rating this wouldn't have likely done better theatrically than its 5 screens and $135,000 gross.