Box Office Report: 'Mortal Instruments' Opens No. 1 Wednesday With So-So $3 Million

The $60 million adaptation of Cassandra Clare's YA book stars Lily Collins as a teen who discovers she's part of a secret order of half-angel warriors.

The Mortal Instruments: City of Bones, the latest supernatural film property based on a best-selling YA book series, debuted at No. 1 Wednesday with a tepid $3 million.

Starring Lily Collins as a girl who discovers she's part of a secret order of half-angel warriors, the supernatural pic is on course for a five-day debut in the $15 million range. It earned a B+ CinemaScore.

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This weekend, City of Bones will have to battle Edgar Wright's dark comedy The World's End, headlined by Simon Pegg and Nick Frost, and horror pic You're Next, which both open on Friday.

City of Bones is a major gamble for Germany's Constantin Films, which financed and produced the $60 million movie. Sony's Screen Gems acquired U.S. rights to the title, the first in a planned franchise. If it does prove soft in the U.S., Constantin is hoping to make up the difference overseas.

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Directed by Harald Zwart, City of Bones is based on the first book in Cassandra Clare's popular YA book series. There are currently five books in the main series, with a sixth and final book due out in 2014. Clare has sold an estimated 24 million copies worldwide including spinoffs and prequels to the main series.

The story, about a teenage girl who discovers the supernatural world around her, bears obvious parallels to another popular YA film series -- The Twilight Saga. But other YA adaptation films that have been released in 2013 have stumbled at the box office. Beautiful Creatures opened in February in sixth place with $8.9 million at the domestic box office, behind Warm Bodies, which was in its third week of release. And then in March, an adaptation of Twilight author Stephenie Meyer's next book, The Host, became a disappointment when it landed in sixth place its opening weekend, grossing only $10.6 million -- less than one-third of the first-day gross of the first Twilight film in 2008 ($35.98 million).

Constantin is already gearing up to shoot the second film in the Mortal Instruments franchise, with a planned production start in mid-September.

E-mail: Rebecca.Ford@THR.com

Twitter: @Beccamford