Ned is probably the nicest guy ever. He's a good natured, laid back hippie, and even though he might be too trusting, and a little too honest, his heart's in the right place, and his optimistic outlook on life is just too charming to not get into. Contrary to the title, he's not really that stupid, but he is a little low on common sense.
After serving a brief time in jail for selling weed to an on duty cop, Ned loses his home, dog, and girlfriend, so he seeks help from each of his three sisters, satying with each until he can get back on his feet. Unlike Ned, they have a more realistic view of the world, and actually act like adults, unlike the manchild everyone but himself sees him as. Each sister tries their best to deal with him, but one by one he manages to screw up their lives in some very big ways.
Given that Ned is undoubtedly a hippie, and the way the film was marketed, it seems at first glance like a silly, dumb, and typical manchild comedy a la Step Brothers. In actuality, this is actually a very funny, smart, and charming film that isn't afraid to get a little genuinely dramatic and serious at times. There's a seen where Ned finally snaps and has a breakdown, and it's a very effective scene that really shows that Rudd is a gifted actor, and not just of the comedic variety. After that point though, the film feels a little uneven, and the film kinda starts to take the easy way out, but it ends nicely enough.
Aside from that, and that the flm overall is a little tonally uneven, it's still pretty solid, and a lot better than the trailer makes it seem. This is a hard film to dislike, and Ned's outlook on life, though perhaps a little too altruistic, is actually a nice way of seeing the world. I'm probably the msot thankful that the film takes characters that, played or handled by anyone else, would have been treated as throw away caricatures, resulting in a less interesting and probably weaker film.
The film's got a wonderful cast, and they all do a great job. Rudd shows he's got some real chops, and his turn as Ned really holds the film together. It's a finely observed performance that really handles the character type in a nuanced and balanced way. As Ned's three harried and diverse sisters, Elizabeth Banks is great as the somewhat bossy Miranda- a journalist for Vanity Fair working her butt off to get her big break, Zooey Deschanel is solid (though perhaps too obvious) as the bohemian/hispter artist Natalie, and Emily Mortimer is pretty good as Liz the frustrated and uptight housewife and mother of two. Shirley Knight plays mom to all these kids, but she's not really used a whole lot, so they could have been fine without her.
In good supporting roles are Rashida Jones as Natalie's girlfriend Cindy the lawyer (yes, that's right, Rashida Jones and Zooey Deschanel get intimate with one another), Steve Coogan is solid as Liz's boring, pretentious filmmaker husband (who absolutely loathes Ned), and Adam Scott as Miranda's neighbor and best friend. I used to not care for him, but he's proving himself to be a reliable character actor and bit player.
All in all, this is some really good stuff. It's entertaining and funny, but also quite charming and heartfelt. I think the resolution of everything could have been smoothed out better, but it ends well enough, so I can't complain too much. Give this one a go. It's not the dopey raunch fest it comes off as, but is instead a very refreshing and well done dramatic comedy.