Hedda Gabler. With the MIT Community Players at Kresge Little Theater, October 10, 11, 16, 17, 18, at 8 p.m. Tickets $2.75 at the door.

Kennedy's Children. At the Wilbur Theatre, 252 Tremont Street, October 9-October 25, 8 p.m., with matinees Thursday and Saturday at 2 p.m.

Oedipus Rex. Sophocles' classic. At the Lyric Stage, 565 Boylston, Boston, through November 13. Performances Friday-Sunday, 8 p.m., Sunday matinee at 3 p.m.

Pieces and Quiet. Pocket Mime Theater, 67 Newbury Street. Previews October 9-11, 8 p.m., $2.

The Proposition. Science Center B, October 12, 2:30 and 4:30 p.m. Tickets free to GSAS students.

Sizwe is Dead. At the Charles Playhouse, 74 Warrenton Street, through October 19. Performances Tuesday through Saturday evenings at 8 p.m., Sunday evenings at 7:30 p.m., Saturday matinee at 2 p.m., Sunday matinee at 3:30 p.m.

Time of Your Life. At the Brandeis University Theater, through October 18. Performances Friday and Saturday at 8:30 p.m., Sunday at 7 p.m.

The Proposition is a Cambridge classic, so if you've missed it up to now, this weekend might be a good time to catch them. If you've seen them before, though, expect to be disappointed. For one thing, improvisational theater tends to pall after you've seen a particular group several times, since you inevitably begin to notice how much of their act isn't really improvised at all. If they're any good, in fact, the framework within which they improvise is probably pretty carefully and completely worked out. The first time I saw the Proposition, almost five years ago, I was amazed at their inventiveness and wit. How can they do it? I kept asking myself. By the sixth time I knew.

Also, the Proposition had some definite labor troubles last spring, and the cast I saw this year was unrecognizable. There were five actors this time instead of the usual four (perhaps each one was only expected to be four/fifths as good) and one of them, whose uneager ineptness reminded me of some pre-meds I've known, insisted on pronouncing the name of Portugal's General Goncalves as "Gonzalez." It was a letdown after what I'd come to expect; but anyone who's never seen the old Proposition will undoubtedly be duly impressed this weekend. At the Science Center.

Kennedy's Children. This new play beginning its pre-Broadway run at the Wilbur this weekend was a success in London, so it might be worth checking into. It's by American playwright Robert Patrick, and its cast includes Shirley Knight, Kaiulani Lee, Barbara Montgomery, Don Parker, Michael Sacks and Douglas Travis.