A gambit, an attack, a blunder, a sacrifice, and, finally, checkmate! Former University photographer Bob Matthews captured the intensity of these unidentified chess players on the lawn in front of Nassau Hall during Communiversity in April 1986. A popular springtime event that highlights cultural offerings of town and gown, Communiversity this year will take place from noon to 5 p.m. Saturday, April 25. Live entertainment, children’s activities, food, and more than 150 vendors will be featured on Nassau and Witherspoon streets, according to the Arts Council of Princeton, which co-sponsors the event with the University.