Box office: 'Harry Potter' and 'Captain America' battle this weekend

I wouldn’t want to be the superhero that has to go up against Harry Potter — not even Voldemort could handle that kid — but Captain America: The First Avenger will do his very best to take down the wizard at the box office this weekend, and it should be a very close race. Given its huge opening last weekend, Potter is guaranteed a major drop this time around, but it still has a solid shot at number one. Captain America, meanwhile, is battling a trend of diminishing returns that have plagued superhero movies this summer. Also opening is the raunchy rom-com Friends With Benefits, which hopes to continue the recent hot streak R-rated comedies have enjoyed. Who will succeed and who will fail? Take a look at my box office predictions below.

1. Captain America: The First Avenger: $52 million

Captain America is in a very scary spot. The $140 million Paramount picture, which the studio hopes can launch a whole Avengers franchise, is coming just a few weeks after Green Lantern majorly disappointed at the box office. Although earlier superhero flicks Thor and X-Men: First Class fared marginally better, the superhero movie stock seems to be on the decline. If there’s one hero that could save the genre’s performance in 2011, though, it’s the super recognizable and patriotic Captain America.

Perhaps due to the fact that Paramount didn’t screen Captain America until this week (which strikes me as odd — the film has a wonderful look and has earned some strong reviews), the buzz for Cappy has been a bit low. I think this factor, when combined with competition from Harry Potter, will probably lead to a softer opening weekend, although the retro adventure film may endure better than other recent superhero entries. Captain America is playing in 3,715 locations, 2,511 of which will show the movie in 3-D and provide a nice box office boost. I think it could earn about $52 million over the next three days.

2. Harry Potter and the Deathly Hallows—Part 2: $51 million

The final Harry Potter film has already made a boatload of money, earning $214.9 million in just six days and helping the Potter franchise become the top-grossing franchise in box office history. Whenever a movie opens to numbers that big, only one thing is certain: it will fall hard in its second weekend. That’s not to say that Deathly Hallows — Part 2 won’t make a lot of money this week — remember, we’re dealing with astronomical numbers here — the movie could plummet 70 percent and it would still pull in about $51 million.

That’s the kind of hefty drop I’m expecting from Harry Potter this weekend. I’m guessing the wizard flick will fall by about the same amount as The Twilight Saga: New Moon did in its second weekend. Both films opened to enormous Friday grosses, but proved to be rather front loaded over the rest of the weekend. Still, even with a major drop, Harry Potter may end up in first place once again this weekend. We’ll have to wait and see!

3. Friends With Benefits: $23 million

Justin Timberlake and Mila Kunis have been hitting the pavement hard and pushing this $30 million Sony comedy, which has been earning pretty solid reviews overall. This combination of reviews and heavy promotion has helped Benefits arise as a formidable contender at the box office, rather than just “that other friends with benefits movie” (the similarly themed No Strings Attached earned $70.6 million back in January).

R-rated comedies like Horrible Bosses, Bad Teacher, Bridesmaids, and The Hangover Part II have found major success this summer, and I see no reason why Friends shouldn’t join that club as well. Coming out so soon after Horrible Bosses might hurt the film’s prospects a bit, but I see Friends With Benefits skewing to a younger crowd, so competition shouldn’t be too much of a problem. I’d bet that the film, which is playing in 2,926 theaters, will improve upon No Strings Attached‘s $19.7 million opening and find a strong $23 million this weekend.

4. Horrible Bosses: $11 million

The revenge comedy held up very well last weekend, falling by just 37 percent to $17.8 million. This weekend, the film faces some direct competition from Friends With Benefits, but it should be able to hold pretty well again. Benefits has been playing above Transformers all week, and R-rated comedies just can’t seem to be stopped this summer. A 40 percent drop would give Horrible Bosses about $11 million and push its total over $80 million.

5. Transformers: Dark of the Moon: $10 million

The robot/alien spectacle crossed $300 million this week, but its falling quickly. Harry Potter served as substantial competition last weekend, and Captain America will fulfill that role as well. Transformers will likely fall by about 55 percent in its fourth frame (the same drop as last weekend) to $10 million.

Follow Grady on Twitter: @BoxOfficeJunkie