Genpei Kassen

Genpei Kassen (源平合戦, Literally: Genpei War), is a historical simulation game which focuses on the war between the Genji (Minamoto clan) and the Heike (Taira clan) at the end of Japan's Heian period (12th century).

Heike Monogatari serves as the game's prominent reference, but other folktales and fictional stories are integrated as well. References to events found within historical records are present but are often overshadowed by episodes made popular by romantic fiction.

Unlike other historical simulations at the time of its debut, Genpei Kassen has remained primarily for personal computers. It's not as popular as a result.

Gameplay
The player can only command figures from the Ise-Heishi, Seiwa-Genji, or Oshu-Fujiwara clans in each scenario; other clans and forces of the war are controlled by the game's AI. Although the influence each clan has changes depending on the scenario, each clan has a set of general traits to distinguish themselves:
 * Seiwa-Genji - mighty warriors with strong ties of loyalty; diminutive supplies and no trade threatens domestic security; specialize in archery
 * Ise-Heishi - high political influence and excellent domestic trade; constantly harassed by multiple rivals in most scenarios; excel in naval warfare
 * Oshu-Fujiwara - distant from warfare in most scenarios; rich domestic and economical resources yet lacks capable generals for war

Victory is achieved by either absorbing enemy territory or by eradicating rivals completely from the map. Defeat occurs when the player loses all of their territory.

Genpei Kassen follows a monthly turn-based system which is split into two halves: the domestic and combat phases. The domestic phases oversees troop supplies, available gold, and troop training within one or more of the ally provinces. Ally generals can be ordered to transport goods, initiate trade, or recruit additional generals. Harvests, plagues, and weather affect these stages like other historical simulations. To protect their monthly earnings, however, the player will need to spend a portion of their finances erecting bases of public security. While costly to build, these bases lower losses caused by rebels or thieves.

Political prestige of ally generals is another important factor to consider in the game's planning phases. At one point in their conquests, the player must appease the cloistered Emperor Go-Shirakawa with elaborate poetry readings, political visits, or parties. Pleasing the retired emperor increases the maximum troop capacity for armies and the number of provinces which can be ruled under their command. A higher standing with the imperial court also affects the multiple houses of noblemen in the game, whose trust and confidence is required for conquering provinces beyond the player's starting point.

Depending on the player's character, certain houses will refuse to ally themselves due to historically noted differences between them. A character's historical political standing also affects their likelihood of gaining the court's favor. Genji retainers, who are mostly within the samurai caste, will struggle. Members of the Heike, who are largely considered nobles throughout the game, have an easier time.

Prestige is a fluctuating trait. If the player neglects to keep favorable relations with the court, their character's immunity and fame will drop. Loyalties between generals will suffer, and troops will be harder to recruit. At extreme levels, the clan under the player's control will not be acknowledged and will cease to exist. Manipulating the political standing of rival clans is encouraged to support the player's conquests.

Once the player is confident in their resources, they can assemble an army to attack a rival general. Troops simply need to move onto an enemy general or base on the map to commence combat. Before the battle begins, the player can manually configure their army's formation. They can also choose to pray to the gods for a random boost in morale, challenge the enemy general to a duel with one of their officers, or fight normally.

Although battles are still turn based, the player can order their troops only on the first turn. Actions within the battle are determined by the game's AI without the player's intervention. Commands the player can issue per character are straightforward offensive (such as "Attack" or "Distract") or defensive ("Withdraw" and "Avoid") tactics. If the player has skilled archers, they can order them to stay at the rear for a rapid-fire volley. Special abilities, such as avalanches and cavalry charges, can be ordered if the terrain allows. Win or lose, every battle must be concluded within ten turns.

If conflicting generals of high acclaim come in close proximity of one another, they might initiate a duel sequence. The power of their strikes is determined by morale and their War stat. Certain generals may even invoke a special technique to deal critical damage to their opponent. Participants in duels risk death in battle or capture if they should fail. A losing general may plead for mercy and their escape, which causes their instant withdraw from battle if it is permitted by their opponent.

Scenarios
Similar to other Koei historical simulations, the player begins their game by first selecting a scenario. Scenarios include: The Heike are powerful in the first two story paths, but the Genji will have the clear advantage for the other half. The Fujiwara clan remain resourceful yet ambivalent in every scenario. Like early Nobunaga's Ambition or Romance of the Three Kingdoms, animations and duels can be turned off. Historical events are automatically triggered based on the game's date, yet the player can actively prevent them from occurring. Killing Yoritomo before Kiyomori succumbs to illness, for instance, will never trigger Kiyomori's historical death in the first story path.
 * 1) Yoritomo Lays the Foundations of Kamakura (October 1180): Kiyomori's conquests, Yoritomo's exile and rise within the Hōjō
 * 2) Yoshinaka Seizes The Capital (July 1183): Yoshinaka's insurgent forces collide with Yoritomo, Munemori's succession of the Heike
 * 3) Heike Restoration at the Western Sea (October 1184): Situation of the war after the Battle of Ichi-no-tani, Heike have lost property and start stranded within the west
 * 4) Yoshitsune Slays His Brother's Adversaries (October 1185): Battle of Dan-no-ura, contention between Yoritomo and Yoshitsune in Oshu

The time spent in each scenario is limitless, only ending once the player has either lost or claimed victory. At any time, the player may choose to leave their side's actions to the game's AI.

Related Media
Koei released a handbook of the game summarizing the historical setting and figures for players' convenience.