Climate change is coming to SimCity.

A new version of the city-building computer game that factors in real-world consequences of energy choices has won endorsements from Twitter co-founder Biz Stone and the director of the Academy Award-winning documentary "An Inconvenient Truth."

"We are updating SimCity with technology of today and introducing it to a new generation of gamers," Maxis studio senior vice president Lucy Bradshaw said at this year's Game Developers Conference in San Francisco.

"It gets under your skin; exposes you to the idea of cause and effect and that choices you make have repercussions," she said.

Millions of people have played SimCity since the computer game designed by Will Wright was first released in 1989.

The original title won a broad, devoted following and led to a successful franchise of "Sims" strategy games in which players manipulate worlds and animated characters in simulations of real life.

"Sims 3 Showtime" software, released on Tuesday as an addition to the latest version of the game, lets players act out fantasies of becoming famous singers, acrobats, magicians or DJs.

The $40 expansion pack adds a host of features, including one allowing players to send their characters into other people's games via the Internet with a capability called "SimPort."

While the franchise has thrived, it has been nearly a decade since the release of the last version of SimCity for desktop or laptop computers. A Maxis team will have a fresh SimCity title ready in 2013, according to Bradshaw.

Along with rich 3-D graphics, the game will have a new simulation engine that enhances its realism and extends ramifications of urban design decisions past borders to affect neighboring cities.

"In 'SimCity' resources are finite, you struggle with decisions people are struggling with today in the real world and your decisions can have a global impact," Bradshaw said.

"Be a polluter and you are ultimately going to affect your friends' cities... Will you have the wealthiest, fittest, greenest city ever or the sludgiest, most yikes-worthy SimCity ever?"

Maxis collaborated on the title with Games For Change, a group devoted to the creation of games that combine fun with learning about social issues.

"I love the game," said "Inconvenient Truth" director Davis Guggenheim, who played an early version with his son.

"Climate change is the biggest crisis of our time, but there is a disconnect because it is not in front of us," he added.

"When you play 'SimCity' it is in your face; if you build a coal power plant you feel the consequences -- smog in the city, water table getting dirty, and your people getting angry."

Twitter co-founder Stone is also among the early fans of the new "SimCity," which he said was in tune with his new initiative to support systems that help make "better humans, a smarter world and a healthier planet."

Stone left his day-to-day role at Twitter last year to devote time to Obvious Corporation, which he established with fellow Twitter co-founder Evan Williams and Jason Goldman.

"While I'm not a gamer I understand the learning power of play," Stone said.

"Learning the cause and effect and the impact you could have as an individual or a corporation is huge... The 'SimCity' overview puts us in that frame of mind."

Bradshaw noted that 'SimCity' has always blended realism and fantasy, "so you never know when a giant lizard might trundle around a corner and blow your buildings down."