The best after-dinner games need no special equipment to play: no dice, cards, tiles or machines that bleat at wrong answers. Classics like charades and the dictionary game — sometimes called Fictionary, and tweaked for the unimaginative under the brand name Balderdash — call at most for paper and pencils. They’re D.I.Y. and lo-fi.

As Christopher Hitchens reminded us in his memoir “Hitch-22,” even paper and pencil are sometimes superfluous. He described a game, played with Salman Rushdie and other friends, that involved replacing the word “love” in famous book titles with the phrase “hysterical sex.” (They played dirtier versions of this game too.) Thus you’d get titles like “Hysterical Sex in the Time of Cholera.”

In my extended family, over the past decade, we’ve looked forward to playing something we call the book game, which I am going to retitle, for the purposes of this article, the paperback game. Introduced to us by friends, it’s been kicking around forever, handed along by word of mouth. (A narrow version of it was packaged in 1991 under the brand name Ex Libris.) Some of you may have played the paperback game; I’m guessing many of you haven’t. It’s time to plug this small but vital gap in your education.

I think of the paperback game as a summertime entertainment, best played in beach and lake houses and old inns, all of which tend to collect visitors’ random and abandoned books. So the weekend of the Fourth of July seems like a good time to share, review and/or clarify the rules. From here you can bend them to your will and make the game your own.