Stallone was always a better actor than Schwarzenegger. That burning question, for those old enough to have asked it and deluded enough to have never figured it out, is answered once and for all in “Escape Plan,” a vintage prison escape movie in the classic Sly and/or Arnold mold.

They’re both in it, both locked up and both looking for a way out of a super prison that has all the escape-proof conveniences that private enterprise can cook up. The old pros hit their marks and each other. They spill some blood and have theirs spilled.

Sly takes a few beatings and hunts for that one epic brawl with a bad guy, a guard played by Vinnie Jones. Ah-nuld finally speaks his native German in a Hollywood film in a long, deranged rant and tracks down the biggest gun available.

A few one-liners and catchphrases — “You hit like a vegetarian!” — and there you have it, Sly and Arnold in their heyday, in a nutshell.

Stallone plays Ray Breslin: “I break out of prisons for a living.”

He wrote the book on how security is compromised in maximum security prisons, and he co-owns a security company. He’s inserted into prisons which he then breaks out of so that he can then teach federal officials how to make their prisons more escape-proof.

His new challenge is a super-secure “secret” prison set up for the C.I.A. and run by private contractors. It’s a place for terrorists and their ilk, people who need to disappear. Ray goes in, but his team (Amy Ryan, rapper 50 Cent) have their safeguards in place.

Only they’re foiled. There’s no tracking Ray, no telling where he’s been taken to and no way of explaining who he is so that he can get out.

In the cavernous new prison, there’s no sunlight. Cells are all glass, the guards wear black storm trooper suits and sci-fi face masks. Solitary confinement is a cell with blinding high-intensity lights. And the warden (a whispering Jim Caviezel, pretty good) is a fastidious fussbudget who collects butterflies, constantly checks his suit and tie and has just a hint of sadism about him: “You’re here, now. And you belong to me.”

Director Mikael Hafstrom (“1408,” “Derailed”) is at his best studying his stars and their surroundings in extreme close-ups. We catch the details Ray does, only to figure out later what those details mean to him. The action arc here is predictable. But the standard prison-issue fights in the “yard” (indoors) or mess hall are handled well. The Islamic bad guy (Faran Tahir of “Elysium”) has dimensions, even though the head sadist (Jones) doesn’t.

The bonding scenes between Ray and the big, friendly Teutonic terror Rottmayer (Schwarzenegger) are clumsily written but have their amusing moments. The heroes have great hair and makeup. And the escape plans have a pleasant dose of “MacGyver” about them.

Villains are a tad too obvious, and the finale you can see coming from miles off. And 50 Cent is still a terrible actor, though he’s now sporting Hollywood dentistry.

So, yeah, it’s undemanding. But the tempered violence, the nature of the villains, the easy bonhomie of our leads and a cast peppered with great supporting players make “Escape Plan” go down easier than the other “Rambo”/”Last Man Standing”/”Expendables” pictures that brought these two aged action stars back from the dead.