The original Mega Man series began in 1987 and established the franchise name. Set in the year 200X, it depicts a world transformed by advances in artificial intelligence and robotics. Two leading engineers, Dr. Light and Dr. Wily, pursue peace and ambition in opposite directions, and Light's household robot Rock repeatedly thwarts Wily's schemes through his own sense of justice. The core games are action titles known for their difficulty, and this branch remains the largest in the Mega Man franchise, including related spin-offs.