Blackjack is card game played with a standard 52-card deck, similar in broad outlines to Uno. (It’s not to be confused with the card game of the same name, also known as Vingt-Un, Pontoon and other names.)
There are many games of this basic type. This version is sometimes called Taylor Blackjack, because it gets played a lot a big, raucous house-parties at our home in summer.
In my experience, the particular rule-set of Blackjack is tuned to make the game funny to play, rather than especially challenging or skillful. For this reason, it is by far my favourite card game.