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Cairn

2nd Edition
Explore a dark and mysterious Wood filled with strange folk, hidden treasure, and unspeakable monstrosities
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fantasy
Rules-LightExplorationClasslessDeadlyDungeon CrawlAttacks Always HitOpen SourceGrittyInventory ManagementFiction-FirstDark FantasyGM-Friendly
Languages: English
Diced20, d4–d12
System FamilyOSR
CostFree / $
LicenseCC BY-SA 4.0
PublisherCairn Press
Year2024
Complexity Very Low
Accessibility Very High
Community Medium

Core Mechanic

Roll d20 equal to or under one of three attributes (STR, DEX, WIL) to make a save; 1 always succeeds, 20 always fails. Combat is simultaneous and attacks always hit — the attacker rolls a weapon die, subtracts armor, and applies the rest to HP. When HP reaches 0, damage spills into STR and triggers a Critical Damage save.

Best For

Groups who want a fast, classless fantasy game where equipment defines the character, expeditions into the Wood are tense and lethal, and the GM can roll most of their prep from tables.

Highlights

Inventory and Fatigue share the same 10 slots, so every spell cast, wound, or burden taken on competes with the equipment that defines a classless character. The Scars table turns surviving a near-death hit into permanent character development — a hit that drops a PC to exactly 0 HP rolls a unique injury or trait that often raises an attribute, making advancement a consequence of surviving danger rather than an XP track. Dungeon turns and three-watch wilderness travel each have their own resolution loop and event table, giving the Warden a structured procedure for both exploration modes instead of freeform improv. The Warden's Guide bundles procedural setting, faction, dungeon, and forest generators alongside the bestiary, so prep can be rolled rather than authored.

Considerations

Starting HP is rolled on 1d6, so first-session characters can be killed by a single hit — Cairn assumes attrition and replacement rather than long heroic arcs. Combat is deterministic: attacks always hit and damage is rolled by the attacker, removing the to-hit decision space some tactical players want. There is no Charisma or Intelligence attribute and no fixed spell list — social conflict resolves through WIL saves, and a character's magical capability is shaped by which spellbooks the party finds rather than choices made at creation. Advancement comes through the Scars table rather than XP or milestones, so growth is a byproduct of surviving damage rather than a steady level-up curve.