Sengoku

Introduction

Welcome to the player wiki for the 4th edition of West Coast MegaGames’ Sengoku ruleset.

Sengoku is a megagame focused on power, politics, warfare, and social maneuvering in feudal Japan during the 1550s. Players take on the roles of daimyo, generals, monks, retainers, diplomats, courtiers, and agents as competing factions struggle to secure legitimacy, territory, wealth, and influence during one of the most unstable periods in Japanese history.

This game builds upon earlier megagame designs pioneered by Jim Wallman and the Megagame Makers. Their influence on collaborative political simulation and large-scale roleplay design has been foundational to modern megagaming and to the development of Sengoku itself.

As with any historical game, compromises have been made between authenticity, clarity, and playability. Sengoku-era Japan was politically and socially complex, and many systems have necessarily been simplified or abstracted. The goal of this game is not strict historical simulation, but to capture the atmosphere, tensions, and competing pressures of the era: legitimacy and ambition, loyalty and betrayal, diplomacy and warfare.

Players are encouraged to immerse themselves in the setting, but are not expected to arrive with prior historical knowledge. The game is designed to support a wide variety of play styles and levels of experience.

Most importantly: players are not expected to learn the entire ruleset.

Sengoku is intentionally structured around overlapping sub-games: warfare, governance, diplomacy, court politics, and intelligence operations. Different players naturally specializing in different systems. A successful clan depends more on communication and coordination than on any single player mastering every mechanic.

This document should be treated as a handbook and reference guide, not a fully exhaustive rulebook. Certain mechanics, systems, and consequences are intentionally hidden or only partially explained. Discovery, experimentation, negotiation, and uncertainty are all part of the intended experience.

The Sengoku Period

The Sengoku-jidai, “the Age of Warring States”, was a prolonged era of civil conflict that dominated Japan from 1467 to the early 1600s. Central authority fractured, alliances shifted constantly, and military strongmen competed for control of the country.

Japan was traditionally governed through a layered hierarchy:

• The Emperor served as the divine sovereign and symbolic head of state.

• The Shogun ruled as military dictator in the Emperor’s name.

• The Bakufu administered the Shogunate and enforced military rule.

• Regional daimyo governed provinces through networks of retainers, vassals, warriors, and local officials.

The collapse of central authority began during the Ōnin War, when disputes between rival clans spiraled into nationwide conflict. Over the following decades, ambitious warlords seized territory, overthrew rivals, ignored imperial authority, and reshaped the political order through force and diplomacy alike.

By 1551, the authority of both the Imperial Court and the Ashikaga Shogunate stands dangerously weakened.

In the west, the powerful Sue Harukata has turned against his former lord, contributing to the chaos surrounding the Tainei-ji Incident and the destruction of much of the Imperial Court’s political structure. Court nobles have been scattered, imperial authority has been humiliated, and confidence in the old order has begun to collapse.

Meanwhile, in Kyoto, the ambitious Miyoshi Nagayoshi and the Miyoshi faction increasingly dominate the capital through military intimidation and political maneuvering. The Bakufu remains nominally intact, but its authority is openly challenged and increasingly dependent on whichever clans can impose order by force.

The current Shogun, Ashikaga Yoshiteru, is young and politically isolated. Emperor Go-Nara has largely withdrawn from public leadership following the violence and instability surrounding the court. Across Japan, many now question whether the traditional order can survive at all.

Yet legitimacy still matters.

Titles, court rank, honorable conduct, military success, alliances, hostage exchanges, marriage ties, religious support, and imperial recognition all continue to shape political reality. Armies may seize land, but only legitimacy can secure lasting authority.

Some clans seek to preserve the old order. Others intend to dominate it. Still others believe the realm has already fallen apart and that power alone now determines legitimacy.

It is at this moment of uncertainty that the game begins.