We hadn't seen a trailer for this in the theater but the local paper gave it a good review so we decided to see it. Imagine a world where no one can lie. This is the premise. Not only can nobody lie, but everyone seems compelled to say whatever is on their minds, no matter how hurtful, revealing or unfeeling it is. When Mark (Ricky Gervais) picks up Anna (Jennifer Garner) for their first date, she tells him right off that she wasn't really looking forward to their date, finds him unattractive and most likely will not date him again. He just accepts this as the way things are.As you might expect, this makes for a pretty depressing society. The young, attractive, well off people (like Anna) are pretty happy because other people are always giving them complements. When Mark and Anna get to the restaurant for dinner, the sort of dumpy hostess says to Anna "I feel threatened by you". On the other hand, people like Mark are mostly unhappy. When the waiter comes to their table he tells Mark that his date is way out of his league. This doesn't sound very funny but the movie has a lot of funny moments.
The writers put in a lot of effort to take this world to some not so obvious conclusions. For example, there are no words for lying or truth. When Mark discovers he can lie, he has a hard time describing it. The best he can do is say "I said something that isn't". There is no literature or fiction writing of any kind. Mark is a screenwriter. Movies consist of a person reading about some historical event (there can't even be actors in such a world). Mark's specialty is 14 century Europe, the time of the Black Death, which nobody wants to hear about.
Mark learns that there are some definite advantages to being able to lie, for example at the casino (when he buys his chips the girl tells him that the games are rigged in favor of the house) he can outrageously cheat because they believe everything he tells them. But when he gets a beautiful woman in a hotel room by telling her if they don't make love right away the world will end (to which she says "Do we have time to get to a motel or do we have to do it right here?) he can't go through with it because it would be wrong.
The humor is mostly situational (not much slapstick) and is adult in nature (and by that I mean grownup, not based in sex). We really liked it and strongly recommend it.