Plot

A man and a woman are compelled, for legal reasons, to live life as a couple for a limited period of time. At stake is a large amount of money.

Set in Sin City, story revolves around two people who discover they've gotten married following a night of debauchery, with one of them winning a huge jackpot after playing the other's quarter. Unhappy pair try to undermine each other and get their hands on the money -- falling in love along the way.—Marisa_Gabriella

Joy McNally is driven career woman who is engaged but when her fiancé grows tired of her uptight attitude; he breaks up with her. Jack Fuller is a guy who likes to goof off, which makes his boss who also happens to be his father, fire him. Feeling down they both go to Las Vegas to forget about what happened to them. When they get there, a computer error puts them in the same room. And after getting drunk, they wake up to discover they got married, which they both want to get out of. But when they win 3 million dollars, the ownership of which comes into question. When they decide to take it to court, the judge decides that they should remain married for 6 months and attend counseling sessions. So Joy moves in with Jack. And they both learn that if one of them asks to get out of the marriage, the other will get the money. So they each try to drive the other to want to get out of the marriage.—rcs0411@yahoo.com

After a wild night out of hard-partying and drowning their sorrows in dazzling Las Vegas, by a twist of fate, Jack Fuller and Joy McNally end up married. Of course, to continue this fiasco back in New York is out of the question; however, when a staggering $3 million in slot machine winnings come between the unhappy newlyweds, things are bound to get complicated. Now, Jack and Joy must stay together to discover the joys of matrimony and prove that they can make it work if they want to get their hands on the grand prize. Could that fateful trip to Vegas be the prelude to true love?—Nick Riganas

The clumsy and reckless Jack Fuller is fired by his boss and father and together with his friend and unsuccessful lawyer Hater, they decide to go to Las Vegas to have a good time. Meanwhile the fiancé of the workaholic stock broker Joy McNally breaks up their engagement because of her lack of attitude. Her friend and bartender Tipper convinces Joy to spend a couple of days also in Las Vegas. Due to a hotel management mistake, they are lodged in the same room and later they hang around together. During the night, they get completely wasted and on the next morning, Jack and Joy find that they got married. While discussing to briefly end their wedding, Jack borrows a coin from Joy to gamble in the jackpot machine and wins three million dollars. They question in court the ownership of the money and the conservative Judge R. D. Whopper freezes the money and sentence them to live together with Joy moving to Jack's house for six months and attending regular counseling sessions. Each one decides to make the life of the other hell on Earth to force to get out of the marriage.—Claudio Carvalho, Rio de Janeiro, Brazil

In New York City, high-strung equity trader Joy Ellis McNally (Cameron Diaz) is dumped by her fiance at a surprise birthday party she throws for him, because of her uptight attitude. At the same time, easy-going carpenter Jack Fuller (Ashton Kutcher) is fired from his job by his father, Jack Sr (Treat Williams). Both become emotionally distraught and, with best friends Toni "Tipper" Saxon (Lake Bell) who's a bartender, and Jeff "Hater" Lewis (Rob Corddry ), a lawyer, take a debauched trip to Las Vegas.

Joy and Jack meet by chance when they are given the same hotel room because of a computer error. After clearing up the misunderstanding and receiving upgraded rooms and coupons to various clubs, they party and drink together and end up getting married. The next morning, they realize it was a mistake and decide to divorce.

Before they do so, Jack uses a quarter Joy gives him in a slot machine. He hits a three million dollar jackpot and Joy reminds Jack that they are married and hence, she is entitled to half of the money. The couple return to New York, where they attempt to divorce. The judge declares that the couple cannot divorce until they attempt to co-exist for six months, while attending weekly sessions with Dr. Twitchell (Queen Latifah), a marriage counselor. If they work at the marriage but still want to divorce after six months, each will be permitted to keep half the winnings. If either party does not cooperate, the money will be tied up in litigation by the judge. They both learn that if one of them asks to get out of the marriage, the other will get the money. So they each try to drive the other to want to get out of the marriage.

The newlyweds devise more and more cunning schemes to undermine each other, such as Jack telling Joy that their counseling session is canceled to prove she's not committed, and Joy inviting girls to their apartment to try to get Jack to cheat on her, throwing a party where Jack's friend Dave (Zach Galifianakis) shows up. Jack gives Joy's ex-fiance, Mason (Jason Sudeikis), her engagement ring back without Joy knowing. However, at Joy's job retreat, Jack and Joy find themselves developing an unexpected attraction to one another, and they soon realize that being with each other has brought out the best in both of them.

After they get back from the retreat, it's time for the judge to decide what happens to the money. On her way to the hearing, Joy sees her ex-fiance Mason, and he tells her that he wants her back. He gives her back the engagement ring and tells her that she is good enough for him. Joy realizes that Jack set her up to get back with Mason and cheat on Jack so that they will be divorced. Joy walks away from Mason and goes to the hearing. At the hearing, their marriage counselor testifies that the couple tried to work on their marriage. The judge decides that they will split the remaining 1.4 million dollars (after taxes, bills Joy ran up, and money Jack spent on his new woodworking business). Joy tells the judge she doesn't want any of the money and as she leaves she gives the engagement ring to Jack, telling him she doesn't want anything from him.

Joy gets the promotion she'd been working for, but declines it, telling her boss she would rather be happy doing nothing than doing something she hates and being miserable. Jack's parents tell him they think it looks like he and Joy are in love. Realizing his mistake, he goes to find her. Tipper tells Jack that she quit her job and that nobody knows where she is. He suspects that she has gone to a beach (Fire Island, New York) that she told him about as the only place that makes her feel truly happy. Finding her, Jack asks her to be his wife (again) and she says yes.

Epilogue During the closing credits, there are scenes from the day Jack and Joy get married, of Tipper and Hater subsequently enacting a plan of revenge on Mason, and of Hater cutting off Dave.