At first glance, it might seem easy to adapt fantasy fiction for television. After all, it’s made up anyway, so it should be no biggie beyond the cost of special effects, right?

Not at all, of course. To oversimplify, making fantasy fiction credible is more of a challenge than adapting realistic fiction because you need to work harder to get viewers to suspend disbelief. And that takes great writing.

We have no doubt at all, for example, that there are seven kingdoms, a wall of ice and an iron throne, not to mention dragons, in “Game of Thrones.” But it takes a while for us to let go of our skepticism when it comes to a young bride on her honeymoon in post-World War II Scotland who is suddenly transported two centuries back in time and wakes up with full consciousness of her 20th century life.

That’s the premise for the new Starz’ drama “Outlander,” premiering at 9 p.m. Saturday. It’s based on the hugely successful series of fantasy bodice-rippers penned since 1991 by Diana Gabaldon.

Since 1991, some 25 million “Outlander” series books have been sold in 26 countries and translated into 23 languages. The newly released “Written in My Heart’s Own Blood,” the eighth book in the series, has a press run of 500,000. That’s a half mil in actual books – those things with pages and covers and without a battery in need of recharging.

Fans of the books won’t need any help suspending disbelief when the first of 16 initial episodes airs Saturday, but other viewers may. That said, once they buy into the richly charactered story, it’ll be an even bigger challenge to let go.

The war has finally ended and Claire Randall (Caitriona Balfe, “Super 8”), who worked as a battlefield nurse, is finally reunited with her new husband, Frank Randall (Tobias Menzies, “Rome”), who was attached to MI6 during the war. Their reunion is awkward at first, but both hope that a delayed honeymoon in Inverness will rekindle the intimacy they’ve had to put on hold.

Things do warm up a bit, but while on a hike, the couple come across an ancient circular arrangement of vertical stones, Claire is drawn to the tallest of the stones, places both hands on its surface and is hurled back to 1743.

All of a sudden, British Red Coats are thundering through the underbrush chasing kilted Scots. Claire tries to get away and is suddenly face to face with... her husband? Except it’s not her husband: It’s his sadistic ancestor, Black Jack Randall. He’s about to have his way with her until the dashing and exceptionally hunky Jamie Fraser (Sam Heughan, “Emulsion”), intervenes.

In short order, Claire is taken prisoner by members of the MacKenzie clan and brought to Castle Leoch. As an English woman, she’s suspected of being a spy, but once she begins using her 20th century nursing skills, she is seen as a healer and the MacKenzies let their guard down, just a bit.

Claire adapts rather well to life at the castle – perhaps too well, at first. It is understandable that writer-producer Ronald D. Moore wants to get us into Claire’s new life quickly, but realistically, if you were to suddenly awaken 200 years in the past, you might be a little more than just mildly perplexed when you realize where you are. Not Claire.

We also may question how much she really misses her husband, given how readily she begins flirting with Jamie. And, again, the point is to move the plot and hope we’ll go along for the ride. Eventually, we do, but not as quickly as Moore hopes.

In fact, Claire’s transition is more credible in Gabaldon’s book than it is on screen, and for an obvious reason: Television is a different medium, and needs careful writing and correct pacing to convey significant plot or character developments which might take several pages to unfold in print.

Moore’s script doesn’t do that. What it does do, to the show’s occasional detriment, is to mimic the sometimes stilted dialogue from the book. Few may think twice when they hear Frank say to Claire as they are saying good bye in the middle of the war, “Don’t take any unnecessary risks,” but really: That’s what he’s saying to his wife? It sounds like he’s talking to an underling in the British secret service.

Yet, despite these problems, even the most cynical viewer may find him- or herself caught up in the drama because of the appeal of the characters, convincing performances and a careful attention to detail in costumes, sets and production design.

Balfe, Heughan and, in one of his two roles, Menzies form a vibrant trans-century love triangle. All three more than overcome the handicap of sloppy dialogue to keep our attention focused on their characters. We are able to invest in Claire’s growing emotional conflict between her future husband Frank and the strapping young Jamie because of the depth of Balfe’s performance.

The supporting cast is every bit as terrific as the main cast. Gary Lewis (“Silent Witness”) plays Colum, the powerful laird of Clan MacKenzie, showing us the man’s strength and his determination not to be pitied because of a crippling disease of the legs. Graham McTavish (“24”) is the laird’s brother and the clan’s war chief, a scheming, untrustworthy man who nonetheless shows Claire a degree of mercy later on.