Overview

Diadem is a grand-scale galactic conquest game published by Fantasy Games Unlimited in 1981. Players compete for control of a galaxy, managing military forces across space and ground theaters while also engaging in politics, economics, espionage, propaganda, and scientific research. The game is played on a hex mapboard divided into 12 sub-maps, creating a large and varied playing field for interstellar warfare and diplomacy.

Components

• 1 large hex mapboard divided into 12 hexagonal sub-maps
• Unit counters for space fleets and ground forces
• Resource and technology tracking sheets
• Cards or charts for espionage, propaganda, and politics
• Dice
• Rules booklet

Setup

1. Assemble the mapboard from its 12 sub-maps.
2. Each player selects a faction/empire and places starting forces and homeworld markers.
3. Set initial resource levels, technology tracks, and political positions.
4. Determine turn order.

Turn Structure

Each game turn:

1. Political Phase: Conduct diplomacy, form alliances, and resolve political actions.
2. Economic Phase: Collect resources, build units, and fund research.
3. Research Phase: Advance technology tracks to unlock new capabilities.
4. Movement Phase: Move space fleets and ground forces across the map.
5. Combat Phase: Resolve space battles and ground invasions.
6. Espionage/Propaganda Phase: Conduct covert operations against rivals.
7. Administrative Phase: Update control markers, check victory conditions.

Actions

Space Combat

• Fleets engage in space battles when they meet in the same hex.
• Fleet composition (ship types, technology level) determines combat strength.

Ground Combat

• After achieving space superiority, ground forces can invade planets.
• Ground combat is resolved separately from space combat.

Hyperspace Travel

• Fleets can use hyperspace to move rapidly across the map, but routes may be limited or contested.

Economics and Production

• Resource collection from controlled planets funds unit construction and research.
• Balancing military spending with research and espionage is key.

Espionage and Propaganda

• Conduct sabotage, intelligence gathering, or propaganda campaigns against rival empires.
• Successful espionage can weaken opponents without direct combat.

Scientific Research

• Invest resources to advance technology, unlocking better ships, weapons, and capabilities.

Scoring / Victory Conditions

The player who controls the most territory (or achieves specific galactic domination objectives) at the end of the game wins. Alternatively, controlling a set number of key planets or eliminating all rival empires can trigger an immediate victory.

Special Rules & Edge Cases

• Multi-Dimensional Strategy: Success requires balancing military conquest with economic management, research, and covert operations.
• 12 Sub-Maps: The modular map creates a large play area with varied geography and strategic chokepoints.
• Long Play Time: Games can last 3-6+ hours due to the strategic depth and number of systems to manage.
• Hyperspace Routes: Control of hyperspace lanes can be as important as controlling planets.
• Diplomacy: Player negotiation and alliance-building is significant, especially in games with more players.

Player Reference

Turn Phases: Political → Economic → Research → Movement → Combat → Espionage → Administrative

Key Systems: Space combat, ground combat, hyperspace, economics, research, espionage, propaganda, politics

Win: Control the most territory or achieve domination objectives

Strategy: Balance military, economic, research, and covert operations