The regrettable part of Intimate Exchanges is that the only people who can truly recognize the ambition of Alan Ayckbourn’s script are the director, the actors, and anyone willing to sit through 16 performances. Based on chaos theory, the play opens with Celia, the anxiety-ridden wife of an alcoholic headmaster, making a small decision, setting the course of action in one direction or another, each of which has two possible second acts, each of which has two possible endings. In case you’re doing the math, that only adds up to eight variations. Director Kurt Beattie limited Ayckbourn’s script so as not to drive the actors insane; after all, there are only two of them. Marianne Owen and R. Hamilton Wright have taken on the challenge of portraying all six characters, rapidly changing dialects and costumes to farcical effect, a feat all the more impressive when you realize they’ve memorized another seven versions of the play. Owen and Wright have done an excellent job with the exceedingly British humor, though I’m afraid some of it is lost on those of us with American ears. BRENT ARONOWITZ ACT Theatre, 700 Union St., 292-7676. $10–$66. 2 & 7:30 p.m. 7:30 p.m. Tues.-Thurs. & Sun., 8 p.m. Fri.-Sat., plus some matinees. See Web site for exact schedule (and to find out which ending will be used). Ends Sept. 14.

Tuesdays-Sundays. Starts: Aug. 15. Continues through Sept. 14, 2008