
The Entertainment Software Rating Board was established in 1994 to assign ratings to video games. With the rise in popularity of mobile applications on smartphones, they are set to expand the coverage of its rating system.
CTIA, the international organization that oversees the wireless communication industry, announced that it has partnered with the ESRB to introduce a content rating system for mobile apps. The group refers to the new plan as a "mobile application rating system," suggesting it will reach beyond the realm of games.
The Apple App Store and Google Android Marketplace currently feature user-based rating systems. Apple employs a numerical rating system (4+, 9+, 12+, and 17+), while the Android Marketplace uses a text-based system (Everyone, Low maturity, Medium maturity, and High maturity). Although it is unclear how the ESRB's new system will be integrated into existing stores, it could provide a more universal scale.

Marvel's Spider-Man 2 ESRB rating is set to "T for Teen" due to "Blood, Drug Reference, Mild Language, and Violence" present in the title.

The Entertainment Software Ratings Board has published the God of War Ragnarok ESRB rating and rating summary.

The addition of in-game purchases is noteworthy as no other game in the series is listed as having these on the official ESRB website.
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UPDATE: The ESRB introduced the “in-game purchases” label in 2020. It has been pointed out to us that its presence in relation to Nintendo Switch titles has been regarding the ability to purchase a Nintendo Switch Online subscription and not any DLC or other post-release content. We regret the confusion and appreciate those who’ve brought this to our attention.