Resources
Offical Resources:
Warhammer Community: The Horus Heresy: This is the main landing page for Horus Heresy content on the Warhammer Community website including FAQs, Errata, Additional Rules, Exemplary Battles in the Age of Darkness, Legacies of the Age of Darkness and more.
Legacies of the Age of Darkness: Imperial Militia: Full official Cults and Imperial Militia army list.
Other Narrative Campaigns
So you can get an idea of how others do it overseas, here are some well known Horus Heresy narrative events and campaigns from around the world:
Reference Sheets
Unofficial/Third Party Expansions for HH V2:
These are all unofficial and unsupported, but heavily playtested rules and expansions from the wider Horus Heresy Community. While we aren’t using them currently - they may provide inspiration or additional content for our narrative campaign in the future. Of particular interest is the Rogue Traders Militant army list in Liber Imperatus.
Liber Panoptica: Unofficial community FAQ, Errata, and Balance Changes, as well as new Game Modes, Mission packs, and a full Crusade system
Liber Imperatus: Unofficial expansions for four existing sub-factions of the Imperium - Legio Custodes, Sisters of Silence, Imperialis Militia, Solar Auxilia - as well as an entirely new sub-faction, the Rogue Traders Militant
Liber Ingenium: Unofficial expansion for new generic units, specialist units and characters, wargear, and more for the Mechanicum
Liber Centura: Unofficial expansion for new generic units, specialist units and characters, wargear, and more for all space marine legions
Liber Antiquia: Unofficial expansion for sub-factions of the Eldar - the Craftworld Asuryani, and the Harlequin Saedath
Unofficial/Third Party Expansions for HH V1 (Outdated):
While out of date, these unoffical, but often used expansions are a great source of ideas for narrative, play formats, missions and more
Mournival Events Rulebook: V1 Centurion and Decurion Rules, new weapons, assassins, units, characters and strategems + bonus content for Adeptus Titanicus