There’s a game you see sometimes at improv comedy shows called, depending on the troupe doing it, “Faster Faster” or “Half Life.” In it, the actors improvise a scene one minute in length, then re-do the scene in 30 seconds, then again in 15, then in seven, then 3 1/2. The comedy comes from seeing them scramble not just to remember what they did, but to do it in half the time.

“Basic,” which is not a comedy but should have been, is structured the same way. The first pull-the-rug-out-from-under-you plot twist comes, say, 50 minutes in. The next one comes 25 minutes later, then 12 minutes, then six, then three, and so on. By the time the film ends, the twists are coming at a dizzying pace, and none of them make a damn bit of sense.

John Travolta, in a continuing effort to re-destroy his career, plays Tom Hardy, a DEA agent hanging out in Panama doing I forget what. He’s been disciplined for allegedly taking bribes and is what movies call a “loose cannon.” His old Army buddy, Bill Styles (Timothy Daly), calls him in to investigate the death of Sgt. West (Samuel L. Jackson), a sadistic trainer of rangers who, coincidentally, once tortured Hardy himself.

West died during a training exercise in the jungle, as did a few of his trainees. The survivors are Kendall (Giovanni Ribisi), now dying of bullet wounds, and Dunbar (Brian Van Holt), in fine health. The two have contradictory accounts of what happened, and there are more accounts yet to come, much to the frustration of Hardy and Lt. Julia Osborne (Connie Nielsen), who is upset that an outsider has been brought in to interrogate the witnesses when she could do it just fine herself, thank you very much.

Also, Harry Connick Jr. plays an Army doctor who is a former lover of Osborne’s and a pal of Hardy’s and a few other things that would be considered spoilers if I told you what they were.

The screenplay, by James Vanderbilt (“Darkness Falls”), is a silly exercise in movie tricks. Let’s put a twist here! Let’s have an unreliable narrator there! The director, John McTiernan, who will never be forgiven for “Rollerball” (2002), cannot yield much that is worthwhile from the script, nor from his cast, which has a few talented people among it.

And yet, the film is not without redeeming qualities. Despite its many impossible twists — or perhaps because of them — it is an enjoyably dumb film, the sort of thing that is entertaining for all the wrong reasons. It’s never dull, that’s for sure, the same way interesting dreams are never dull: It may not adhere to any recognizable logic, but it’s a lark while it lasts.

C (1 hr., 34 min.; R, abundant harsh profanity, some strong violence, very brief nudity.)