Final answer:
A play is characterized as "rich" or "richly written" when it features complex and layered characters and dialogue.
Step-by-step explanation:
A play might be characterized as "rich" or "richly written" when it features complex and layered characters and dialogue. While a large budget for production or the play being set in a luxurious environment might enhance its visual appeal, the richness of a play primarily lies in the depth and complexity of its characters and their interactions through dialogue.