Dreams dictionary: Play
Dreams dictionary: Interpretation 1
To dream that you are playing refers to your tendency to go against the norm and break the rules of convention. You are displaying unrestricted creativity. Alternatively, playing implies that you are all work and no play. You need to relax and let loose. On the other hand, the dream may also be saying that you are not taking things seriously enough. You need to face reality.
Dreams dictionary: Interpretation 2
To dream that you are in a play represents the roles you play in your life and the various acts and personas you put on. If you are watching the play, then it suggests that you need to draw from the inspiration of others.
Dreams dictionary: Miller Dream Interpretation
For a young woman to dream that she attends a play, foretells that she will be courted by a genial friend, and will marry to further her prospects and pleasure seeking. If there is trouble in getting to and from the play, or discordant and hideous scenes, she will be confronted with many displeasing surprises. See Theater.