The Gin Game by Donald L. Coburn
WINNER 1978 Pulitzer Prize for Drama.
Weller Martin and Fonsia Dorsey, two elderly residents at a nursing home for senior citizens, strike up an acquaintance. Neither seems to have any other friends, and they start to enjoy each other's company. Weller offers to teach Fonsia how to play gin rummy, and they begin playing a series of games that Fonsia always wins. Weller's inability to win a single hand becomes increasingly frustrating to him, while Fonsia becomes increasingly confident.
While playing their games of gin, they engage in lengthy conversations about their families and their lives in the outside world. Gradually, each conversation becomes a battle, much like the ongoing gin games, as each player tries to expose the other's weaknesses, to belittle the other's life, and to humiliate the other thoroughly.