Susan Choi won the National Book Award for fiction on Wednesday night for “Trust Exercise,” a novel set in the 1980s at a competitive performing arts school, where two students fall in love. The judges praised the novel for blending “the intellectual rigor of post-modern technique with a story that is timely, mesmerizing, and in the end, unsettling.”

Ms. Choi, a Pulitzer finalist in 2004 for her novel, “American Woman,” said in an acceptance speech that she was still surprised and grateful to be able to write for a living.