Some series need no introduction. Five minutes into watching “The Dudesons in America” (9 p.m., MTV), and you’ll swear you’ve seen this all before.

The Dudesons consist of four best friends from Finland, fearless in their pursuit of the slapstick and self-inflicted violence of the “Jackass” variety. But after you’ve seen one dude take a bowling ball to his private parts, you’ve seen them all.

• Macho antics of a more constructive sort unfold on “World’s Toughest Fixes” (8 p.m., National Geographic). Every week host Sean Riley visits job sites where extraordinary tasks are everyday events. First up, he takes us to a Wyoming ski resort trying to reopen its lifts using a smattering of hand-me-down parts. The most exciting aspect of this “Fix” is the use of a heavy-duty helicopter as a kind of crane in the sky.

The uniqueness of these job sites is undercut by the sameness of the presentation and the tough-guy attitudes on display in every loudly amplified scene. At times, it seems like an extended commercial or product placement for pickup trucks. And maybe it is.

• Things don’t add up after a deranged clown kills a math whiz on “The Mentalist” (9 p.m., CBS). There’s got to be a lesson or a metaphor in here somewhere. Or is this just a plea for CBS to renew “Numb3rs” for another season?

• Impossibly suave, multilingual, spectacularly accomplished and dedicated to justice for the oppressed, U.N. diplomat Sergio Vieira de Mello would probably seem unbelievable if he were a character in a novel or on a show like “24.” But Sergio was real, and “Sergio” (7 p.m., HBO) is the story of his remarkable career and tragic death at the hand of al-Qaida in 2003.

Over three decades with the United Nations, Sergio’s path would take him from the Balkans to East Timor and finally to Baghdad during the aftermath of an occupation that he had publicly opposed.

In addition to interviews with U.N. colleagues, including his fiancee, we hear from notable figures, including former British Prime Minister Tony Blair and former Secretary of State Condoleezza Rice. “Sergio” is based on the biography “Sergio: One Man’s Fight to Save the World” (Penguin, 2010) by Pulitzer Prize winner Samantha Power, who is interviewed extensively here. Mixing obvious affection with a journalist’s eye for the telling phrase, she describes her subject as “a combination of James Bond and Bobby Kennedy.”

Tonight’s other highlights

• Grim evidence of witchcraft on “Bones” (7 p.m., Fox).

• A killer stalks those who have escaped fates foretold on “FlashForward” (7 p.m., ABC).

• Michael assigns Dwight to tail Donna (Amy Pietz) on “The Office” (8 p.m., NBC).

• A mother may be behind her family’s disappearance on “CSI” (8 p.m., CBS).

• Martha Plimpton guest stars on “Fringe” (8 p.m., Fox).

• Mothers share their stories on “Bipolar Mysteries: Families in Crisis” (8 p.m., Discovery Health).

• Mothers convene on “30 Rock” (8:30 p.m., NBC).

• Gwyneth Paltrow, Jerry Seinfeld and Greg Giraldo appear in “The Marriage Ref” (9 p.m., NBC).

Cult choice

Jim Carrey stars in “The Truman Show” (7 p.m., TBS), a 1998 satire of reality programming.