Familiar movie themes like animal slapstick, buddy-cop humor and romantic comedy abound in this week's trio of new releases -- "Kangaroo Jack," "National Security" and "A Guy Thing," respectively -- but at least one star was determined to make sure that her character broke from convention.

"On the page, Karen was this woman [who] was distracted," explained Selma Blair, who comprises one third of a love triangle with Julia Stiles and Jason Lee in "A Guy Thing" (see [article id="1459549"]"Selma Blair, Julia Stiles, Jason Lee Make Love Triangle In 'A Guy Thing' "[/article]). "You could see [him] not wanting to be with her right off the bat. I just said, 'I don't want to play the bitchy fiancée again. It's been done a million times. It's obvious. Let's just not have a movie like that. Let's make it a tiny bit more complicated.'

"The truth is, neither of these girls are bad girls," she said of the end result. "They're both good girls. Karen and Becky are decent girls. And just one isn't right for him."

Blair has given heart and soul to an otherwise stiff character before. "Again, on the page for 'Legally Blonde,' she was just an incredible snob from the get-go," she said of her role as Vivian in the 2001 surprise box-office smash. "Vivian Kensington has to be, because these are over-the-top comedies, 'Legally Blonde' even more so than ['A Guy Thing']." Nevertheless, she made sure that by the end of "Legally Blonde," Vivian had become a character worth sympathizing with.

"I like there to be some kind of turn-around where you see that not everyone's your enemy," said the actress. "And I like that my character and Reese's character in 'Legally Blonde' could come to terms with each other, and it doesn't have to be a fight. And I'm pretty protective of my characters in that way."

Despite her character's growth in "Legally Blonde," Blair isn't returning for the sequel (see [article id="1457667"]"It's Witherspoon Versus Washington In 'Legally Blonde 2' "[/article]). "They're shooting that right now, and there's no more room for Vivian. She kind of played herself out, her arc. This one's all about Reese's character going to Washington. And she's much more of a woman. It's really her having her own thing instead of a buddy."

Sequels are something Martin Lawrence knows a lot about, as a year after he and co-star Steve Zahn ("Saving Silverman") wrapped filming on "National Security" he started work on "Bad Boys 2" with Will Smith (see [article id="1456163"]" 'Bad Boys 2' Co-Star Gabrielle Union Says Flick Will Be 'Crazy Action' "[/article]). Like "Bad Boys," "National Security" relies on lots of jokes, car chases, gunplay and crime busting.

Speaking of criminals, Jerry O'Connell ("Jerry Maguire") plays a guy who has a bunch of money stolen from him by a kangaroo in "Kangaroo Jack."

The Golden Globe-nominated "The Hours" (see [article id="1459227"]" 'Chicago' Leads Pack Of Golden Globe Noms; Eminem Nabs Only One"[/article]) also goes into wide release this week, following an impressive limited run in select theaters.