Ragnarok Online

Ragnarok Online (RO) is an MMORPG created by Gravity Interactive LLC of South Korea. Much of the background of the game is based on the graphic novel Ragnarok by Lee Myung-Jin. Currently, there are versions of the game in Korean, Japanese, English (better known as International RO or iRO), Thai, and Chinese. Most if not all versions are now pay-to-play and are continually being revised and revamped.