The episodes take place in New York and feature fan favorite characters from the entire run of the Law & Order franchise, including flashback scenes with Lennie Briscoe. The gameplay is similar to the Pheonix Wright series of games. Every episode is an individual case in which case is investigated first and then tried in court, like the show. Also like the show, it's possible to lose the court battle but the game doesn't end. There's multiple outcomes depending on how you do in court. Like most of Telltale's other games, and especially Telltale's later CSI games, the individual cases will be tied together at the end of the series.
You can buy Law & Order for Mac and PC here and for iPhone, iPod Touch, and iPad here (The iOS version is a universal app. The first episode is available with the app, the remaining episodes can be purchased within the app individually or in a season package). Episodes 1,2,3, and 4 are available now for iOS. The remaining episodes will be released at a later, as of yet unannounced date.