Tera developer Bluehole Studio, claiming theft of intellectual property. The developer is comprised of former NCSoft employees, and the publisher is accusing them of stealing "copious amounts of confidential and proprietary NCsoft information, computer software, hardware, and artwork relating to Lineage 3," and using them to create Tera.
“Their business plan was simple and audacious: create a competing product using the very work they had done while at NCsoft, launch it themselves to great fanfare and acclaim, and, in the process, deal a crippling blow to their former employer," accuses NCSoft's documented complaint against Bluehole.
This legal case has been active since 2009, when a Korean court convicted the group of stealing trade secrets from NCSoft. Those convictions were largely upheld by an appellate court. However, NCSoft's civil complaint for damages against the group were overturned after a successful suit for damages and an injunction against Tera being published. Both Korean civil and criminal cases are still under appeal.
Since the injunction was overturned, the Korean version of Tera launched a year ago, while the North American launch is due to be published by En Masse this May 2012.