The 3DO Rating System was a rating system created by The 3DO Company

The 3DO Company

The 3DO Company , also known as 3DO , was a video game company...

 and used on games released for the 3DO Interactive Multiplayer

3DO Interactive Multiplayer

The 3DO Interactive Multiplayer is a video game console originally produced by Panasonic in 1993. Further renditions of the hardware were released in 1994 by Sanyo and Goldstar. The consoles were manufactured according to specifications created by The 3DO Company, and were originally designed by...

. The rating system has four categories:

• E - Everyone (e.g., The Incredible Machine, Gex
  Gex (video game)
  Gex received mostly positive reviews. Aggregating review website GameRankings and gave the 3DO version 79.58%, the PC version 71.00%, the Sega Saturn version 69.35% and the PlayStation version 63.33%....
  
  )
• 12 - Guidance for 12 & under (e.g., Star Wars: Rebel Assault
  Star Wars: Rebel Assault
  Star Wars: Rebel Assault was the first CD ROM-only game published by LucasArts, set in the Star Wars universe. It was released for the PC followed by subsequent releases on the Sega CD, Mac and 3DO platforms.-Summary:...
  
  )
• 17 - Guidance for 17 & under (e.g., Killing Time
  Killing Time (video game)
  Killing Time is a horror-themed FPS video game with Full-Motion Video components, developed by Studio 3DO. Though meant at first as an exclusive for their 3DO Interactive Multiplayer console, it was later ported to the Windows 95 PC platform in 1996 by Intrepid Software and to the Macintosh when...
  
  , Demolition Man
  Demolition Man (video game)
  Demolition Man is a multiplatform action video game based on the film of the same name with running and gunning elements. The player controls the main character, John Spartan as he attempts to find and defeat his arch-nemesis, Simon Phoenix...
  
  , Plumbers Don't Wear Ties
  Plumbers Don't Wear Ties
  Plumbers Don't Wear Ties is an adult graphic adventure game produced and released by Kirin Entertainment in 1994. Kirin's first published game, John and Jane are being pressured by their respective parents to find a suitable spouse, and it's up to the player to get John and Jane together...
  
  )
• AO - Adults Only (e.g., Onee-san to Issho! Janken Paradise, Twinkle Knights)

These ratings would appear on the lower front and back of the packaging, while the back of the packaging also specified what content was present in the game. This rating system was discontinued after the Entertainment Software Rating Board

Entertainment Software Rating Board

The Entertainment Software Rating Board is a self-regulatory organization that assigns age and content ratings, enforces industry-adopted advertising guidelines, and ensures responsible online privacy principles for computer and video games as well as entertainment software in Canada, Mexico and...

was established in 1994 and from then on, 3DO games were rated by ESRB.