December 17, Capcom releases the first Mega Man game in the long-standing series for the NES/Famicom.
December 18, Square's Hironobu Sakaguchi releases Final Fantasy for the Famicom in Japan. This was originally intended to be the company's last game, since it was facing bankruptcy, but the game's major success allowed them to turn it into a prolific series ironically titled Final Fantasy. It was released in the U.S.A. 3 years later.
Nintendo of America, Inc. v. Blockbuster Entertainment lawsuit: Nintendo sues Blockbuster for photocopying complete NES manuals for its rental games. Nintendo wins the suit, and Blockbuster includes original manuals with its rentals.