Will Ferrell and John C. Reilly star as Brennan Huff and Dale Doback, two 40 year old men who still live at home with their respective single parents, Mary Steenburgen and Richard Jenkins respectively. Nancy and Robert meet at a convention, fall in love, get married and move in together, along with their adult children. And there's your set up. Naturally, Brennan and Dale hate each others guts at first, but then grow to like each other when they realise how much they have in common. But the mess and destruction that they cause prompts Robert to demand that the boys get jobs and move out, but of course, nothing goes quite that smoothly.
It has to be said, there are a lot of laugh out loud moments in this film, despite the fact that, like Brennan and Dale, the film's sense of humour is in a state of arrested development. But simply because the humour is childish doesn't make it unfunny. The jokes come thick and fast, and enough of them stick that you're prepared to let the others go without too much of a grumble. Like most of Ferrell's films, there are lots of very funny one-liners, and Step Brothers is no exception. (“I'll kill you, Leonard Nemoy!” and “I've travelled five hundred miles to deliver my seed.” spring to mind.)
Adam Scott does very well as Brennan's successful asshole of a brother, Derek. His character feels a lot like an 80's-shark, and takes a punch to the face out of a treehouse for one of the funniest moments in the film. Kathryn Hahn is superb as his wife who hates him, telling Dale, who landed the aforementioned punch, that she “will masturbate tonight thinking about him doing that”. Together with their two children, they very nearly steal the show near the start, with an in-car a cappella rendition of Guns 'N' Roses' Sweet Child O' Mine. Hilarious.
However, for all its humour, there's no getting around the fact the plot is pretty rubbish. Once it has established Brennan and Dale's characters and their relationship, it doesn't really know where to go from there, and so it jumps all over the place, searching for a final scene where they can all learn to simply be themselves. Mary Steenburgen is wasted and Richard Jenkins just gets a bit annoying. It's not the end of the world, thankfully, as the jokes manage to just about carry the film over the line, but you get the feeling that they wouldn't have if the film had gone on much longer.
The acid test as to whether or not you will like Step Brothers, I think, is a scene during the closing credits, in which Brennan and Dale land in a helicopter and beat the crap out of a bunch of bully kids. If that sounds like something that you'd enjoy, then Step Brothers is probably for you. If not, then maybe you might want to give this one a miss. Personally, I laughed my ass off at John C. Reilly spinning on a roundabout, punching child after child in the face, but hey, that's just me. B.