Emil Pagliarulo knows that riveting stories beat at the heart of captivating videogames.

The Bethesda Softworks designer backs his point with "Fallout 3," a post-apocalyptic adventure in which each player starts out as a youth searching for a scientist father and makes moral choices shaping his or her destiny.

"We've really come to the point that game play alone isn't enough to hook gamers; they want and expect great stories," said Pagliarulo.

"It's these stories that pull us in, and keep us interested as we continue playing past the eighth or 80th hour."

Online chat forums reveal players are devoting scores of hours to "Fallout 3," taking on quests such as freeing slaves, rescuing hostages, and integrating an elitist survivor settlement.

Conversations players have with in-world characters affect directions stories take, with choices regarding whether to do good or evil determining their reputations, opportunities and allies.

Videogame makers began evolving into modern-day storytellers in the early 1980s, according to Chris Swain, assistant professor at the University of Southern California where he co-founded Electronic Arts Game Innovation Lab.

Nintendo videogame legend Shigeru Miyamoto in 1981 challenged players to rescue a damsel in distress from an animated giant gorilla in "Donkey Kong."

"Working with a crude computer system with simple pixels and beeps he wanted to make it more of a story where your character had to save the princess from this monster," Swain said.

"At the time, it was very unusual."

As videogame hardware allowed for complex play and more vivid characters, shooter titles abounded catering to "hardcore gamers" seen as young men thrilled by blasting enemies to oblivion.

Pagliarulo recalls a Game Developers Conference a few years ago at which he was chagrined by colleagues that argued stories weren't needed in videogames.

"I thought that was ludicrous then, and I think it's ludicrous now," Pagliarulo said. "The past few years have shown just how important story can be. Games have turned an important corner."

The list of blockbuster role-playing, story-driven videogames is growing. "Halo 3" is credited with being so coveted that it boosted sales of Microsoft Xbox 360 videogame consoles for which it is exclusively tailored.

A new "KillZone 2" science fiction action videogame featuring a contemplative Sergeant Tomas Sevchenko and "Hollywood realism" is expected to be among this year's stellar titles for Sony PlayStation 3 consoles.

Powerhouse French videogame maker Ubisoft last year bought a Canadian film animation company and said it intended to more intimately combine the worlds of movies and videogames.

"Sometimes people play games for the visceral thrill of it, sometimes they are playing the story, and sometimes they are playing for both," said Swain.

"You can make the argument that story is what is compelling people to go through it."

He says recent "breakthroughs" include "Bioshock" influenced by books by Ayn Rand and "Grand Theft Auto IV," the latest installment of a franchise blasted for its depictions of violence.

"If you play 'GTA: IV' you can run around doing whatever you want and get achievements and it has nothing to do with the story; it's a playground," Swain said.

"But, you can also play the story of Nikko Bellic. You have this amazing piece of work that should be respected which also happens to be morally bankrupt."

Mitchell Kernot, 15, has ramped up his "Fallout 3" character's charisma skills to the extent that he proudly claims he can talk his way through tricky in-game situations without firing a shot.

Kernot has disarmed a nuclear warhead, saved strangers in radioactive remains of Washington, DC, and even fought off mutants to recover the US Declaration of Independence.

"If there isn't a storyline with twists and turns, I usually stop after two hours," said Kernot, an admitted videogame fanatic.

"If parents thought their children were immersing themselves in a deep storyline, contemplating morality and the good of humanity, and making moral choices for a side things would be a lot easier for us."

Story-loving players like Kernot are the rule, not the exceptions, according to Pagliarulo.

"Ultimately, the best games are those where that line is so blurred, players don't even know it exists, and game play and story are seamlessly married," Pagliarulo said. "That's always the goal."

As the console wars lead to slicker action, seamless cut scenes and cinematic reality in videogames the people who make them will have increasingly better tools to bring them to life with stories.

"I really do feel that the more believable our characters become, the better our stories will become," Pagliarulo said.

"So I'm really excited about studios and games that pursue this. I'm rooting for them."