Modiphius Entertainment brings the cosmic dread of the Cthulhu Mythos to the Roman Empire’s northern borders. Set in 165 CE, Cohors Cthulhu pits centurions, Germanic warriors, and provincial mystics against elder gods, insidious cults, and strange extraterrestrial invaders lurking beyond the frontier.
The latest offer from the Bundle of Holding delivers the complete digital line released so far for the 2d20 System roleplaying game. Backed originally via Kickstarter in October 2023, the collection gathers essential core guides, regional supplements, and ready-to-run adventures at a fraction of their retail price.
Cohors Core Collection – $14.95
Paying the baseline entry price of $14.95 secures two core digital rulebooks with a combined retail value of $62:
- Cohors Cthulhu Player’s Guide (The complete 233-page core book detailing character creation, historical cultures, magic, equipment, and core rules – $28 retail)
- Cohors Cthulhu Gamemaster’s Guide (The 280-page operational manual for GMs, featuring secret cult factions, legendary relics, creature profiles, Voidforged rules, and adventure tools – $34 retail)
- Cohors Cthulhu Quickstart Guide (An 83-page introductory booklet with six pregenerated characters and a starter scenario)
Cohors Bonus Collection – Threshold Price ($31.25)
Paying more than the dynamic threshold price (starting at $29.95 and sitting at $31.25 at the time of writing) adds four additional titles representing an extra $83 in retail value, taking the total package to $145:
- Cohors Cthulhu – Laurium Adventures (A 160-page campaign sourcebook containing seven standalone scenarios and the Otium downtime system – $20 retail)
- Cohors Cthulhu – Germania (A 200-page setting and adventure expansion detailing tribal territories, Herjan’s Horde, and eight borderland adventures – $28 retail)
- Cohors Cthulhu GM Toolkit (A 52-page rules expansion adding hex-crawling systems, stronghold construction mechanics, and quick-reference GM screens – $20 retail)
- Cohors Cthulhu – The Doom That Came to Vallis (A 20-page investigation scenario focused on ancient serpent sorcery in northern Italia – $15 retail)
Cohors Cthulhu adapts the cinematic Modiphius 2d20 System to historical antiquity, incorporating the friction of cohort warfare alongside Lovecraftian investigation. Mechanically, the engine uses paired d20 rolls against Target Numbers formed by Attribute plus Skill combinations, with critical successes generating Momentum. Players can spend Momentum to purchase additional dice or pass advantages to allies, while failed attempts feed Threat directly to the gamemaster to trigger reinforcements, complications, and environmental hazards.
The setting replaces standard modern Sanity mechanics with historical grit and Roman virtues. A dedicated Gravitas attribute governs stoic leadership, negotiation, and military command under mental pressure. Combat introduces Reach & Guard rules to simulate the physical spatial advantage of shields, pilums, and gladii against charging hordes and towering otherworldly monstrosities. Characters can also weave Runic, Oracular, or Celtic magic, or unearth Atlantean relics to stand on equal footing with horrors that threaten the empire.
All digital files in this collection are completely DRM-free, provided in standard PDF format, plus print-friendly sheets, character generators, and digital maps. The Cohors Cthulhu offer runs through midnight at the International Date Line (UTC -12) on Monday, 9 November 2026.
Quick Links
- Bundle: Cohors Cthulhu
