The games are based on events that took place in China during the 2nd and 3rd centuries, when the land was divided between the Shu Han, Cao Wei and Eastern Wu kingdoms. The games draw ideas mainly from the historical novel Romance of the Three Kingdoms and the historical text Records of the Three Kingdoms.
Gameplay revolves around managing numerical statistics, each representing an attribute of a city or character. For example, a city will have statistics indicating the amount of food stored within its walls, its vulnerability to disasters such as floods and earthquakes, how content the people are with its ruler or governing officer, etc. Characters have statistics to reflect their fighting prowess, intelligence and loyalty towards their respective lords, among other attributes. Players can spend time increasing these numbers before waging war on neighbouring territories, since the artificial intelligence of other lords tends to be peaceful unless the player attacks them first, or unless they have reached a point in the story where war is inevitable.
The seventh, eighth and tenth installments are compounded with RPG aspects, allowing the player to play as a lord, an adviser, a governor, a general or a vassal of another lord, whereas the player controls an entire force in the other editions. In addition, certain characters possess (or can learn) special skills to aid them in war, diplomacy or governance. For example, a general or adviser with high intelligence statistics can lure an enemy unit into a trap or cause the unit to retreat.
There are also several spin-offs based on the series, including Dynasty Warriors, a tactical action video game series, as well as Dynasty Tactics, a hybrid of Dynasty Warriors and Romance of the Three Kingdoms.
Koei has also published three biographical tactical RPGs based on three characters in the series. They are Sangokushi Eiketsuden (Liu Bei), Sangokushi Koumeiden (Zhuge Liang), and Sangokushi Sousouden (Cao Cao).