Perhaps, decades hence, two lifelong friends will dig out all their texts and relive the colorful ups and downs of their relationship, one LOL, OMG and IMHO at a time. Not likely to be very romantic, is it?

Part of the charm of A.R. Gurney's play “Love Letters” is the nostalgia it generates about actual pen-in-hand, substantive letter-writing.

Part of the charm in the current “Love Letters” production at the Hippodrome Theatre is the nostalgia it generates from its performers — Hollywood veterans Ali MacGraw and Ryan O'Neal, who offer telling portrayals of two people who kept in touch via 50 years of correspondence, never quite coming to terms with how much each deeply, crucially needed the other.

It's pretty slender, as stage works go, as the whole thing involves nothing but a couple of actors reading for 90 minutes, seated side by side at a table, avoiding eye contact. But there are good reasons why “Love Letters” has been so durable since its premiere in 1988.

Gurney creates three-dimensional characters right from the first letters of 1937, when Andrew Makepeace Ladd III writes to accept an invitation to Melissa Gardner's 10th birthday party, and she replies with a thank-you note. In short order, we witness the sequence of schools, summer camp, holidays, dances and, of course, attractions.

How Andrew and Melissa draw close and apart and close again makes for an engaging love story, so how could the famous stars of “Love Story” not have a great time with the material?

There's no relation between that 1970 movie and this play, mind you. Still, let's face it, longtime pals MacGraw and O'Neal can't help but spark memories of their screen romance, and that couldn't be a better selling point for a play all about memories.

If this were only an excuse to see the now-70-something actors, the production would sag badly after five minutes of gawking and wondering. (Have they had work done? Gained weight?) But this is the real deal, a staging of “Love Letters” that features two pros delivering the goods.

Such an intimate piece is not ideal for a big house like the Hippodrome, though the subtly amplified performers succeed in drawing you into the experience. They sometimes forget, however, that they're not on a film set. Unlike seasoned stage actors, they frequently forget to pause for laughter (the script is well-packed with wit).

But that proves a minor matter in light of how deftly MacGraw and O'Neal reveal layer after layer of the characters in this staging, directed by Gregory Mosher. They go further in acting than the script calls for, including some teary lines. (Gurney asks actors to “let the audience do the crying.”) The result, though, never feels forced.

MacGraw uses her voice with a musician's ear for nuance, making Melissa a vivid presence, a woman unafraid of speaking her mind or toying with Andrew's feelings, and easily hurt when that doesn't produce the intended result.

Note, too, how wonderfully MacGraw silently mouths a poem O'Neal reads, letting you see just how much the words stayed with Melissa.

In “Love Letters,” reactions are as important as the readings, and MacGraw makes the most of those opportunities. In silent stretches of an annoyed Melissa's refusal to answer Andrew's letters, MacGraw's pouting posture speaks volumes.

O'Neal likewise does some deft reacting throughout. As for the readings, he might trip over a word here and there, but he shines at revealing Andrew's haughty or naughty streak. O'Neal's fine deadpan sense of humor proves useful, too, nowhere more amusingly than in the reading of a dreadful, mass-mailed Christmas letter.

The story of Melissa and Andrew flourishes considerably when experienced through the voices and gestures of two old friends who still clearly retain their own affectionate bond.

“Love Letters” runs through Sunday at the Hippodrome, 12 N. Eutaw St. Call 410-547-7328, or go to tickemaster.com.

tim.smith@baltsun.com