If it only had a heart.

We’re warned right from the opening number that this is “the story of deception, betrayal and more.”

The musical version of THE STING, now trying out at the Paper Mill Playhouse, follows the template of the Oscar-winning film. It isn’t about good guys vs. bad guys; it’s two bad guys against a worse one.

We rooted for the con-men in the 1973 film mostly because of the casting. Paul Newman and Robert Redford, the most charismatically handsome actors of their generation, respectively played the roles of sharpies Harry Gondorff and Johnny Hooker. Audiences who had come to love them in 1969 in BUTCH CASSIDY AND THE SUNDANCE KID – in which they also portrayed robbers — mourned their deaths and wanted a second chance with them.

They got it four years later. Many critics and audiences were so grateful for the chance that they glossed over the lack of morality. Yes, Johnny Hooker wanted to avenge the cruel death of his partner Luther. But he and Luther were guilty in the first place for scamming a bagman for the powerful and feared Doyle Lonnegan.

Given that two wrongs don’t make a right, three certainly don’t. Johnny interests gonif Gondorff to squeeze a fortune out of Lonnegan.

Revenge – for rarely better and usually worse – involves an eye-for-eye level of retribution. Here Johnny and Henry never consider rubbing out Lonnegan (not that there’s anything RIGHT with that), but isn’t stealing money tantamount to just having a murder-demander pay a fine?

Mark Hollman and Greg Kotis – the deservedly acclaimed creators of the 2001 surprise hit URINETOWN – have devised a very fine lyric in trying to excuse at least some of what the men do by citing “The evil that the Depression creates.” It would also remind us that the show takes place in the ‘30s, if the fine, era-evocative, film-noirish music didn’t already establish it. As much as a horse named Blue Note is mentioned, there are many more blue notes in the score.

The talented songwriters can’t maneuver around yet another problem: gangsters and corrupt officials aren’t the types to natively sing.

Are you rebutting by citing GUYS AND DOLLS? That hit offers cartoon characters that, unlike the ones here, never pull a gun. Two romances are main events in that one, while the two couplings here are given so much less stage time that they’re almost (not quite, mind you, but almost) irrelevant.

The stakes aren’t as high in GUYS AND DOLLS, either. Early on, THE STING has a card game that is far more costly than Nathan Detroit’s crap game. As for that Lonnegan heist, Johnny and Henry are looking for a half-million dollars. No, although THE STING will never be confused with such serious musicals as WEST SIDE STORY or SWEENEY TODD, it’s still darker than most.

So where are the tight-lipped men from the film who, as a lyric even admits, hold their cards “close to the vest” instead of putting their cards on the table? That’s especially true during the film’s scene of poker-playing, where they purposely don’t give away too much of themselves. Here Tom Hewitt, playing Lonnegan, joyously sings a cheery bit of song.

Henry does have the bulk of it. That his lyrics become more and more vulgar with every succeeding section is lamentable.

So we’re denied that menacing silence that is the trademark of outlaws in order to make everyone else wonder and worry what they’re thinking. Turning taciturn men into ones who reveal their feelings goes against the grain of who they’ve trained themselves to be.

Hollman and Kotis have given songs that will sound fine on the original cast album. But what did they actually write? The credits for the show do state “Additional music and lyrics by Harry Connick, Jr.” He’s not just a silent partner in the endeavor; he stars as Henry. We can assume that he wrote some or all of the songs he sings — which may be why they’re all so ideal for him.

Connick gets a here-he-comes-yes-it’s-he entrance and gets the applause that Millburn, New Jersey came out to give the star. He croons with Sinatra-ish style, is winning in his book scenes and moves extraordinarily well when required to dance.

So he’s a triple threat, as the revered show bizz term goes? No – a quadruple one, in fact, for we mustn’t forget his skillful way with a piano. In some shows where a performer sits at the piano and then music starts, we wonder if he’s actually playing. Here we know that Connick is truly making the music up there in three separate opportunities to pound and caress the keys. The lights surrounding the proscenium arch suddenly come alive and twinkle. They’re nice to see, but Connick doesn’t need them; he lights up the theater on his own.

Alas, only those on the extreme right hand side can actually see how adept he is. The very nature of piano playing means that most of the attendees will be looking at a seated man’s back. And that’s not much fun.

The-back-to-the-audience bugaboo extends to “The Card Game,” as the song is officially called. Men around a table where they deal and reveal cards never plays well on stage. (That was reiterated by a recent Paper Mill show that braved Broadway and didn’t succeed: HONEYMOON IN VEGAS).

Only mezzanine and balcony dwellers can see what’s truly going on – and neither Paper Mill nor any Broadway theater has more seats upstairs than downstairs. Even from up high, watching cards being dealt and slammed onto a table isn’t visually exciting. Perhaps this is why the songwriters pinned their hopes on giving Connick so many vulgarities in song in order to give something, anything to compensate for the dull stage action.

We’re in an era where audiences who attend musicalizations of movies want to hear the music that the films once gave them. And so, the famous Scott Joplin riffs that beautifully permeated the movie are here, but used in a sparingly now-you-hear-it-oh-you-don’t fashion. The little snippets may not satisfy all who were intoxicated by the film’s music, but for many, the dollop will be enough.

Bookwriter Bob (THE DROWSY CHAPERONE) Martin has added a number of gags to lighten the proceedings; the vast majority of them land. However, he and director John Rando – or anyone else on the staff – should have questioned and rethought a moment that truly stretches credence. After Hooker is cornered by lawman Lieutenant Snyder, he asks for a private moment with his confidant. Would you believe that Snyder allows it and lets Hooker saunter to the other side of the stage for a clandestine conversation? Isn’t he worried that the man is at the very least planning his escape or is about to take it?

Martin has greatly deepened Loretta, the waitress to whom Johnny takes a fancy. Now she has a backstory as an immigrant from the Dominican Republic; Janet Dacal plays her very well. What’s more, Johnny and she share a lovely ballad in “Some Say.”

If THE STING must be a musical, Hollman and Kotis might as well take advantage of three other opportunities for songs. First, when Henry quizzes Johnny on the details he’s chosen, a rat-tat-tat-tat patter song would be more entertaining than rapid-fire dialogue.

A name that’s often mentioned in the show is one that doesn’t appear in the program: Salerno. Some dialogue implies that this character is to be greatly feared; we’ll eventually see why. That said, if Hollman and Kotis had actually written a song called “Salerno” with everyone expressing fear in his own way, we’d remember this character’s name and be more startled than we are now when Salerno emerges as an important ingredient in the story.

The show also needs a number that makes clear what everyone in the betting parlor must do to make the sting successful. There is danger in that, for the writers wouldn’t want to give too much away. Here’s betting that the ultra-talented Hollman and Kotis could do it right.

We’d expect that Connick would be marvelous, but who’s this J. Harrison Ghee as Johnny? A talented newcomer, that’s who. He sings with assurance and is one of the cast’s standouts in enacting Warren Carlyle’s accomplished choreography.

Although Ghee is African-American, this is not a case of non-traditional colorblind casting; the script establishes early on that Johnny is black. In fact, back in the early ‘70s when David S. Ward was conceiving his original screenplay, he initially intended for the character to be black until then-superstar Robert Redford hankered to play the role. Ward wasn’t going to turn down this money-in-the-bank performer and Johnny was suddenly white.

It was a disguised blessing for the film, for it eliminated the problem of believability that we now have. Would hard-boiled criminals in 1936 treat a black man as an equal, as virtually everyone here does? As terrible as it is to say, they would not.

“You gotta have heart,” as a Tony-winning hit musical established many decades ago. THE STING could acquire it quite easily. Don’t have Hooker and Gondorff dupe Lonnegan simply to profit themselves. Instead, have them end the show by presenting the half-million to Luther’s needy widow. Then they become considerate heroes instead of mere self-serving greedy guys.

I can hear the audience now going “Ahhhhhhh!” in delighted approval.