When you put your character on the reader, it unlocks the character in the game, and actually unlocks worlds within the game that are unique to the character.

FORBES: Bobby Kotick On Hatching Skylanders: Spyro's Adventure

Unlike Mario, which was linear, Zelda let you venture in all directions, exploring worlds within worlds, with an array of choice and depth never seen before in a video game.

NEWYORKER: Master of Play

Seth Shostak, an astronomer at the SETI Institute in California, speculated in 2011 that there could be 30, 000 habitable worlds within 1, 000 light-years of Earth, a minuscule distance by galactic standards.

ECONOMIST: Extra-terrestrial life

EA's Sims Online encouraged people posing as avatars to meet, chat and entertain each other within worlds the creators design.

FORBES: A World for the Rest of Us

Many professional athletes like to escape within videogame worlds after a big game or while on the road.

FORBES: Connect

And just as in real life, purchasing an expensive virtual good can send signals of status, wealth and power within virtual worlds and social networks.

FORBES: Creating A $1M Virtual Goods Brand In Second Life

By 2020 an increasing number of people will be living and working within "virtual worlds" being more productive online than offline, the majority of the respondents said.

BBC: NEWS | Technology | Internet's future in 2020 debated

Rather than keeping their distance, the two worlds of moral idealism and decadent debauchery were constantly in dialogue, often within the same person.

ECONOMIST: English history