In June 2015, Maryland-based video game publisher Bethesda Softworks announced at the Electronic Entertainment Expo (E3) that the fourth installment of its post-apocalyptic role-playing game, "Fallout 4," would be coming out that November. But the videogame publisher generated just as much buzz at E3, if not more, by the simultaneous announcement that it had created a mobile preview version of the game, which was available immediately. Within days, "Fallout Shelter" was a hit, and by the end of the month it had beaten "Candy Crush Saga" on the list of top-grossing mobile games, collecting $5.1 million in just two weeks. The numbers were all the more impressive because "Fallout Shelter" was free--players only spent money if they wanted to purchase "lunchboxes" with gear and resources. Bethesda's surprising success with its first-ever mobile game showed that serious game developers can flourish on mobile devices, and that bringing big-name franchises to the small screen might be a worthwhile strategy. Indeed, "Fallout Shelter" served as both a revenue generator and a marketing strategy for Bethesda: when it finally did release "Fallout 4" in November 2015, it was a resounding triumph, with 12 million units sold on launch day to the tune of $750 million.