The Gin Game by D.L. Coburn
The Gin Game, winner of the 1978 Pulitzer Prize for Drama, which originally starred Jessica Tandy and Hume Cronyn, uses a card game as a metaphor for life. Weller Martin is playing solitaire on the porch of a seedy nursing home. Enter Fonsia Dorsey, a prim, self-righteous lady. They discover they both dislike the home and enjoy gin rummy, so they begin to play and to reveal intimate details of their lives.