box office prisonersWarner Bros.

Kidnap drama "Prisoners" has a dark subject, a bleak tone, and big moral dilemmas to chew on, but it became the top movie this weekend not despite its thoughtful grown-up appeal, but because of it. That's as sure a sign as red leaves that summer is over and that the fall awards season is upon us.

"Prisoners" opened with an estimated $21.4 million this weekend, outperforming expectations. It did so, not just because of the star power of its cast (led by Hugh Jackman and Jake Gyllenhaal), but also because of positive advance critical buzz coming out of the fall film festival circuit. Given that the only other new wide-release movie this weekend was the teen-oriented "Battle of the Year," "Prisoners" helped fill what has been a vacuum for grown-up movies at the multiplex, one that typically lasts throughout the summer and ends when kids go back to school.

As it turns out, however, "Prisoners" is far from the only movie currently playing that hopes to appeal to both a nationwide audience of adults and to critics and Academy voters. Several other Oscar hopefuls entered the chart this weekend or held up well from recent openings, establishing themselves as contenders by getting noticed at the box office.

Also opening this weekend (in limited release), for instance, was "Rush," the car-racing docudrama directed by awards regular Ron Howard. It debuted on just five screens but earned an estimated $40,000 on each, a remarkable per-screen average that bodes well for its box office chances when it expands to wide release this coming weekend.

The poignant middle-age romantic comedy "Enough Said" did even better. Opening on just four screens, it scored $60,000 per screen. For a small movie that stars Julia Louis-Dreyfus (in a rare film role) and the late James Gandolfini that hopes attract Academy attention, that's certainly a good way to do it.

These films, like other Oscar hopefuls currently on the box office chart, will benefit from opening early in the season, when there's not so much competition and they're less likely to cancel each other out among ticketbuyers. Already, "Lee Daniels' The Butler" has earned $106.5 million, as it was the first wide-release Oscar movie out of the gate when it opened six weekends ago. Among more limited-release movies, Woody Allen's "Blue Jasmine" has been playing nine weekends and has earned both Oscar hype and nearly $30 million, making it one of the top indie movie hits of the summer and one of the biggest of Allen's long career.

Other possible Oscar movies still charting include "The Spectacular Now" ($6.4 million over eight weeks), "Fruitvale Station" ($16.0 million over 11 weeks) and "Wadjda" (Saudi Arabia's submission to for the Best Foreign Language Film prize), which has earned $135,000 in two weeks.

Of course, box office shouldn't matter to the Academy, which pretends to be interested solely in a movie's artistic worth, not its balance sheet. But there are hundreds of eligible movies, especially among low-grossing independent films, and voters, who may not have time to watch them all, need some way to distinguish the wheat from the chaff. Box office performance is the easiest way for such films to stand out.

Even high-profile, wide-release films may depend on box office to stand out for Academy voters. While they're both weighty dramas, "Prisoners" and "Rush" aren't traditional Oscar contenders, in the sense that they're both genre pictures (crime thriller and racing action spectacle, respectively), the sort of movies that wouldn't even be up for consideration if they weren't also more thoughtful, well-acted, and well-crafted than most genre pictures. For a movie like these, a strong box office finish can make all the difference to the Oscar shortlisters; either one could be the next "Braveheart," "Gladiator," or "The Departed."

After all, the Academy wants to look populist without compromising its standards, so it loves to nominate movies with above-average artistic merit that also happen to be popular hits.

Prisoners- Trailer No.2