A great civic battle is unveiled in “The Art of the Steal,” and the battlefield is one of the world’s finest collections of Post-Impressionist painting.

The world-renowned (and almost literally priceless) Barnes Collection is the prize, a beautifully chosen group of works bought in the early part of the 20th century by Albert C. Barnes, a Philadelphia medical inventor.

As we learn in the opening moments of the documentary, the collection is about to move: from the building specifically designed to house it, just outside Philadelphia, to tourist-friendly downtown Philly itself, where it can generate much more revenue.

Barnes himself is long dead, but this move (the film argues) appears to violate the letter, and certainly the spirit, of his will. For starters, the Barnes building is not a museum but a foundation, which Barnes himself wanted devoted to education, with limited amount of public viewing of the great artworks.

Barnes loyalists testify that the collection can never be moved. The other side — the mainstream Philadelphia contingent — has an argument against every point, leading to a fascinating ping-pong match that’s been going on for years.

“The Art of the Steal” doesn’t leave much doubt about where its sympathies lie. It was funded by a former student of the Barnes Foundation, and its clear implication is that the fix was in from a long way back.

There’s even a hint that the current resolution is the final chapter in a feud that goes back to the 1920s between Barnes and the Philadelphia establishment, as embodied by the Philadelphia Museum of Art and the publisher of the Philadelphia Inquirer, Walter Annenberg.

That might be stretching things, but it makes for an entertaining movie, which “The Art of the Steal” most emphatically is. It’s also a maddening one, and it raises questions that go far beyond the world of art.

If a city’s power brokers can swoop down on a self-contained little enterprise and change the rules (or at least interpret them their own way) in order to end up with all the marbles, it makes you wonder what they can’t do. Whoever “they” is, for that matter.

And with everything else this movie stirred up, you will wonder about the sanctity of having an iron-clad will. It may be signed and sealed, but it turns out other people can mess with it, even if it’s a billion-dollar legacy. Especially a billion-dollar legacy.

“The Art of the Steal” (3 1/2 stars)

Fascinating documentary detailing the drama behind the imminent re-location of the world-famous Barnes Collection of art from its designed suburban setting to a money-generating spot in downtown Philadelphia. The film makes no secret of its opinion on this move, which has resonance beyond the world of art: The fix was in.

Rated: Not rated; probably PG-13 for subject matter

Showing: Seven Gables