For this year’s Super Bowl, marketers want to have fun again.

On the heels of last year’s somber string of ads — particularly a Nationwide Insurance commercial that featured a child who turned out to be dead and elicited almost immediate mockery and criticism online — some advertisers have already said they plan to rely on humor and heartwarming stories during the game on Feb. 7.

On its “Crash the Super Bowl” website, Doritos is asking people to pick their favorite consumer-generated ad from among three spots. The one with the most votes will air during CBS’s telecast of Super Bowl 50.

One ad shows the actress Doris Roberts, best known for her Emmy-winning role on “Everybody Loves Raymond,” whose appearance was obtained through a friend of a friend, using a Tinder-like dating app. A second shows a couple’s ultrasound test going haywire. The third relies on that familiar advertising fallback: cute dogs.

Toyota will air a humorous 60-second spot for the Prius hybrid car during the second quarter of the game, said Jack Hollis, the group vice president for marketing. The spot will kick off a “comedy of errors” campaign for the new Prius and will, Mr. Hollis said, mix humor and drama, and run through the summer.

Mr. Hollis did not provide details on the new Super Bowl commercial but said it would take viewers on a “joy ride,” while simultaneously showing off various features of the Prius. There will not be any celebrity endorsers.

“It will have some tongue-in-cheek humor,” Mr. Hollis said. “It will have a little bit of over-the-top humor.” All of the “highly dynamic” driving shown in the spot will be real, he added.

In recent years, commercials for Toyota featuring Kaley Cuoco of “The Big Bang Theory” and the Muppets have been created by the ad agency Saatchi & Saatchi, Los Angeles.

The feel-good commercials by Toyota, which often takes a comedic approach to Super Bowl ads, and Doritos may come as a relief to viewers after last year’s game.

Nationwide said it wanted to start a conversation by airing a spot from the perspective of a dead child. “I couldn’t grow up, because I died from an accident,” the child said, while a dirgelike version of the Nationwide jingle played in the background.

Mocking memes sprang up on social media deriding the commercial as the worst ad ever. “Nationwide, Your Kids Will Die,” read one.

Coca-Cola and the National Football League aired serious ads about cyberbullying and domestic violence. Nissan added to the viewer ennui with a spot about a racecar driver separated from his son. The father survives a car crash while his family looks on, and Harry Chapin’s “Cat’s In the Cradle” plays in the background.

Not all of the commercials landed flat, however. Budweiser and the agency Anomaly had viewers reaching for their tissues with their “Lost Dog” spot about an adorable pup rescued from a snarling predator by the Clydesdales. “Lost Dog,” the sequel to Budweiser’s 2014 spot “Puppy Love,” connected with viewers and has been viewed more than 30 million times on YouTube.

Snickers and the agency BBDO Worldwide scored with their spoof of “The Brady Bunch,” starring the actors Danny Trejo and Steve Buscemi. The spot is still airing nearly a year later.

“Some years, funny things resonate; other years, emotional things,” said David Lubars, chief creative officer of BBDO. “There’s no way to predict which tone will click with the audience. The thing to do is be different and pure and ignore formulas entirely.”

Advertisers often reflect the prevailing atmosphere during the Super Bowl, which is also their industry’s top showcase. Last year, some brands tried to make a statement about society’s ills. This year, with topics like terrorism, the economy and the presidential campaign prevailing, there is already enough serious news to go around, says Bradley Kay, president of SS&K ad agency.

So he does not expect marketers to repeat Nationwide’s serious strategy. Instead, they will most likely try to offer a brief escape. “People are looking to be entertained at that moment in time,” Mr. Kay said. “I don’t think they want to be depressed.”

“Most people I know had to turn away from the Nationwide spot, it was so upsetting,” he added.

That does not mean serious, or issue-oriented, ads are necessarily always a bad strategy. They can act as counterprogramming in a saccharine sea of cute dogs and talking babies, said Steven Miller of the Rutgers University Department of Journalism and Media Studies.

Although it was “extremely serious,” Apple’s dystopian “1984” ad is still the “granddaddy” of all Super Bowl commercials more than three decades after it aired, he said. Besides, being funny is not easy.

“There’s an old saying: Dying is easy, comedy is hard,” Mr. Miller said. “There’s more of a chance of failing with your product by going for the laugh.”

The ad scene around the Super Bowl has become such a circus that some marketers have forgotten basic lessons, says Ernest Lupinacci, a marketing consultant. For example, just because consumers like your Super Bowl ad in a popularity poll does not mean they will like, much less buy, your product. Sales are the ultimate proof of effectiveness.

Budweiser’s puppy spot was a viewer favorite, but sales for the beverage company dropped in the first half of 2015.

Likewise, a serious ad does not have to mean it is depressing. There were no laughs during Ram Trucks’ stirring “So God Made a Farmer” spot by the agency Wieden & Kennedy during Super Bowl XLVII. But people still talk about the ad and how it moved them.

“Remember the mood of your audience,” Mr. Lupinacci said. “I don’t want a lecture. But you can still do something serious and profound — and move people.”