Black Jack is a Multi Screen Game & Watch game released in 1985 by Nintendo. A Pocketsize version was also released. The model number for the game was BJ-60 (BJ obviously standing for Black Jack). The contents within the box include the Game & Watch unit, LR44 batteries, a caution leaflet, a ball/score leaflet, and battery stickers. For some reason, there are some Black Jack games that were included in white boxes that Nintendo sent out to retailers. The reason for the white box is unknown, though it's also been confirmed that Donkey Kong 2and Super Mario Bros. featured similar boxes.
The game is simply Black Jack on an LCD screen. The game is very different from the standard Game & Watch games. If your cards amount to a combined number of 21, then you win the game. Black Jack is the last Game & Watch video games to be released in Japan. All games released after Black Jack were released only in other countries, despite being made in Japan.