Traditional Chinese is a set of a Chinese characters that do not contain newly created Chinese characters or character substitutions performed after 1946. The modern shapes of traditional Chinese characters first appeared with the emergence of the clerical script during the Han Dynasty, and have been more or less stable since the 5th century.
The term 'Traditional Chinese' is used to contrast simplified Chinese characters. Since the 1950's the government of the People's Republic of China on Mainland China has standardized the use of simplified characters. Outside China, in countries such as Taiwan, the traditional characters are still in use.
Gongjin's Campaign Memorials pretty much always uses traditional Chinese characters, unless it's about something modern-day such as the cardgame Sanguo sha which is written as 三国杀 in simplified Chinese and as 三國殺 in traditional Chinese. It was never released under the traditional Chinese name.
Some Three Kingdoms' names are also written differently in simplified Chinese, some examples: