The last time actress Liza Goddard passed through Oxford professionally, she was touring in play number. 71 by Alan Ayckbourn, Life and Beth, in early 2009. Two years on, she’s at the Playhouse again next week, starring in number 74, Life of Riley (to make the maths work, you must know that the prolific author wrote two in 2008!) “There’s always a dark side to humour,” Ayckbourn says. “If you write a play with all light, you get snow-blind. You have to have shadows to appreciate lightness.”

And darkness there undoubtedly is: the eponymous George Riley is not long for this life, suffering from terminal cancer.

The fact that he never appears on stage is irrelevant: the drama is invested in the impact he has on three couples, and especially the three women, with each of whom Riley has had, or is having, a complex relationship.

Goddard plays Kathryn, a dental receptionist and dedicated performer in amateur dramatics.

“Like the other women,” she told me, “she’s known George for a very long time; the news of his illness comes as a bit of a shock, it changes all their lives and they have to reassess them.

“You know how it is: you trundle along in life and it’s only when something dramatic happens that you start taking stock and ask what you’ve actually done.”

I wondered if, since she’s such a regular in the Ayckbourn acting stable, the playwright has starting writing parts specifically for her.

“He never writes for people, although he may cast them in his head. I have to say I agreed to do this one before he’d written it!

“He’s very good at writing parts for women: they really are women, with women’s thoughts — quite extraordinary. I asked him once how he managed this and he said it’s because he grew up in a house full of women — surrounded by them all the time.”

Liza Goddard is clearly, and hardly surprisingly, a total fan. I tried her on whether he is better at plot or characterisation — “both equally good!”

What about the fact that, because he writes so many plays, these days they become less an event, more “Oh, there’s another Ayckbourn out? Remember, they’re all different. He’s not formulaic. Communicating Doors, which I’m also touring later in a revival from 1994, is a film noir thriller which is also a farce.

“On the other hand, Life of Riley, Alan says, is a watercolour, a very delicate play like a rose. He’s already written number 75! Goodness knows what that’s about!”

There is little latitude permitted when working with Alan Ayckbourn.

“When it’s written, it’s written and you have to learn it absolutely perfectly, including the punctuation.”

I spluttered and Goddard coughed in her Guildford dressing room.

“Oh my word, yes! He once said to me, ‘I think you’ll find that there’s a comma in there: it goes bla comma bla comma bla full stop!’ And I was mortified.

“But, of course, he’s right because that’s the rhythm. In rehearsal, especially close up in the round as in his Stephen Joseph Theatre in Scarborough, if you get the words wrong, he winces.”

She then got technical in a really interesting way.

“Although it’s terrifying, most actors prefer the round, because you don’t have to worry about anything. You just play it in the same technique as playing a television, only louder.

“You have to be real all the time — there’s nowhere to hide. And the other thing is, the audience laughter is so huge in your ears.

“A lot of this goes back to ancient story telling, you know, sitting in a circle round the camp fire.”

After that, you almost feel sorry for Liza Goddard, going into a proscenium theatre like the Playhouse; but then you realise that this no-nonsense actor is having the life of Riley doing Life of Riley.

And what’s the betting Ayckbourn will cast her again in 75?

Life of Riley is being staged at the Playhouse from February 7 to 12.