Computer Entertainment Rating Organization
Computer Entertainment Rating Organization (CERO) is the organization that rates videogames and computer software in Japan with levels of rating that informs the customer of the nature of the product and for what age group it is suitable. It was established on July 2002 as a branch of Computer Entertainment Supplier's Association, using Entertainment Software Rating Board as a model and became an officially recognized non-profit organization in 2003.
|A — All ages: (Equivalent to the ESRB's EARLY CHILDHOOD, EVERYONE, and EVERYONE 10+ and PEGI's 3+ and 7+). It is often likened to the Eirin's "G" Rating.|
|B — Ages 12 and up: (Equivalent to the ESRB's TEEN and PEGI's 12+). It is often likened to the Eirin's "PG-12" rating.|
|C — Ages 15 and up: (Equivalent to the PEGI's 16+). It is often likened to the Eirin's "R-15" rating.|
|D — Ages 17 and up: (Equivalent to the ESRB's MATURE)|
|Z — Ages 18 and up only: (Equivalent to the ESRB's ADULTS ONLY and PEGI's 18+). It is often likened to the Eirin's "R-18" rating.|
One of the symbols above is displayed on the front of the package. This mark is the notation of the age suitability based on the contents. The Z rating may not appear to be very different from the D rating, the only difference is that the Z rating is regulated under the government.
 Contents descriptor icons
In April 2004, CERO defined the following "contents descriptor icons". These icons are displayed on the back of all packages except those rated as "All ages".
- Love (Examples: Sakura Wars, Grandia 3)
- Sexual (Examples: Super Robot Wars, Sakura Wars, The King of Fighters)
- Violence (Examples: Dynasty Warriors, Metal Slug, The King of Fighters)
- Horror (Examples: Tendou Dokuta 2, Ghost Hunter only)
- Crime (Examples: Burnout, Genso Suikoden I&II)
- Use of Alcohol or Tobacco
- Use of drugs
- Language or other
 Classic Ratings
The symbols the CERO used were stylized depictions of numbers, meant to convey at a glance a game's suitability:
|All ages: (Equivalent to the ESRB's EVERYONE and PEGI's 3+ and 7+). This rating was replaced by "A".|
|Ages 12 and up: (Equivalent to the ESRB's TEEN and PEGI's 12+). This rating was replaced by "B".|
|Ages 15 and up: (Equivalent to the ESRB's MATURE and PEGI's 16+). This rating was replaced "C".|
|Ages 18 and up: (Equivalent to the ESRB's MATURE or ADULTS ONLY and PEGI's 18+). This rating was replaced by the two ratings "D" and "Z", setting the age levels where "D" is for ages 17 and over, and "Z" is for ages 18 and over only (Adults ONLY).|
- The first title that rated "Ages 18 and up" is Dead to Rights on Xbox (Released in Nov. 28, 2002).
- As of 2005, the following titles are games on Nintendo hardware that rated "Ages 17 and up":
- Due to societal and cultural differences between the eastern and western worlds (especially the United States and Canada), some titles rated "All ages" by CERO are rated very differently outside Japan (hence the term "rating system deviation"), such as:
- Even though the word "computer" is in its name, the CERO mostly deals with ratings of console games and not PC games.