Wednesday, December 22, 2021

Game Review: Cairn

Author: Yochai Gal
Cairn cover by CosmicOrrery
Publisher: Self-published
Marketplace: DrivethruRPG,
Engine: Mark of the Odd / Knave Hybrid

I have played the hell out of Cairn over the last few days. It is a strange, fun and fast hybrid of the OSR's two popular open Engines: Knave and Mark of the Odd, with a few clever twists of its own.

Cairn tends to favor MotO: it uses its three stat model, highly lethal combat system, and armor/hit point rules. This means that combat is a last resort unless you can guarantee an ambush or superior position. Attacks always hit and do damage by weapon type unless the attacker is at significant disadvantage or advantage, at which point the die changes to a d4 or d12, respectively.

Knave lends its equipment slot system (although all PCs have a fixed 10 slots), and a stripped-down d10 version of it's tables for virtue, vice, misfortune, reputation, clothing, skin, hair face, and build. It also has its own variant set of Knave's d20 tables for determining random character equipment. In addition to randomized name tables with a distinctly Anglo-Saxon selection of names. 

Cairn also uses Knave's magic system: characters carry spell books that represent a single spell. However the spell can be cast multiple times; each time a spell is cast it causes fatigue, which fills an inventory slot, a note from Mausritter that I really appreciated.

Alternative spell lists that include spells that deal some damage, along with random character tools and other expansions are available on Cairn's homepage.

Cairn doesn't have a level system like its parent games do instead, characters burn scars whenever they drop to zero hit protection, but don't lose points of strength. When they take these i stars, after they look great they may roll dice to increase maximum hit protection or certain abilities scores as prescribed based on the injury that dropped them to zero. This takes the idea that "that which does not kill me makes me stronger," and interprets of quite literally in the game.

Karen is specifically set at the edge of a large haunted wood full of ruins of some past cursed civilization. A realm haunted with goblins and trolls and vicious animated plans. It takes a lot of its inspiration from Gavin Norman's Dolemnwood setting.

Mechanically, the game is unforgiving. If you play it in the cavalier style of a new school game, player characters will drop like flies. This is mitigated by having a very clear philosophy of play, including what I would consider the best practices for an old school GM, and some of the best play advice I've seen for players for a narrative focused game. When you play Cairn as suggested, it is a very engrossing experience.

What I Loved


I was tempted to repost the entirety of the advice for GMs an players in Cairn, because it is such solid advice for playing in an Old-School style that it is worth sharing. Because the book is free and worth your time, I will share some favorites:

Cairn is CC-BY-SA 4.0 Yochai Gal

Cairn is CC-BY-SA 4.0 Yochai Gal


The scars system is a cool method of advancing the character: it suggests that the lessons learned from hardship and pain are the ones that teach the most. It is an organic way of developing that ignores the old levelling paradigm and makes advancement feel earned.

Implied Setting

Cairn doesn't give a lot of setting details aside from a paragraph in the introduction:

"Players act as hardened adventurers exploring a dark & mysterious Wood f illed with strange folk, hidden treasure, and unspeakable monstrosities." (Cairn, p. i)

Outside of that, the setting is constructed by way of tables. The name tables are filled with Middle-English and Danish names, and the equipment includes halberds, brigandine, gambeson, and objects like folk songbooks (carried by Friars) which puts the whole thing in a late-Medieval (Tudor) England analog.

The Forest for its part is haunted by "root goblins," Druidic "hooded men", stone "cobblehounds," and beautiful, immortal, and capricious "frost elves."

These handful of evocative names do more for world-building than some setting books can do in a chapter 

Conversion Guidelines

Cairn has a solid system for converting OSR monsters for use with it (and almost any other MotO system.) It made it quite easy to run random Donjon adventures to test it out.


I played a few games of Cairn with my six year old, and he picked it up well enough that he intends to GM it himself. That is a high endorsement.

Open Culture

Cairn is offered under a CC-BY-SA license. Anyone can build material for Cairn or a game based on it so long as it is listed under a similar licence and credit Yochai Gal for the design.


Like both the games it has evolved from, Cairn has no glasses. But it does have that is quite handy are a set of equipment kits that allow a character to step into the role of some traditional D&D character classes at the beginning. This may be the purest level-less and classless game that still has recognizable D&D DNA in its design.

What Power Curve?

Even after receiving a few scars, assuming they receive any, a character rarely feels more powerful than a second or third level D&D player character, if that. There is no power curve that will lead to scalability issues in Cairn.

Growth Points

Show Me More

The setting we got a peek at is very interesting. I would have loved to see a little more with four more pages that offered us a tiny example dungeon and possibly a home base designed to show us more.

There are a handful of additional adventures that I suspect do this. I may review them later 

Background has No Bearing on Character

Your character background in Cairn has no bearing on your character whatsoever, except possibly character knowledge or an advantage on an odd to check here and there. And that is at the GM's discretion. I would have liked to have at least seen one piece of equipment based on background be granted to a character like in DCC RPG. It was disappointing to roll a magician background, and have the character start with no spell books.

MotO's Levelling is a Hard Cut

The narrative based leveling system integral to mark of the odd must have been extraordinarily difficult to cut. It is such an amazing system for building campaigns. I feel that we lose something by removing the strong incentives the system gave to getting characters involved in it evolving campaign world.


This is one of those games where it is hard to find enough complaints for my article

 It is a pretty good game for quick and dirty OSR game. I do have my doubts about extended campaign play, as many of the tools that make Into the Odd excellent for campaigning are stripped down in favor of its unique advancement system.

On the up side, it allows games to remain at a low level where characters can remain consistently challenged. 


  1. Oh man I have this one. I'll have to check it out.

    Regarding obvious traps. I like that. It seems kinda cheap to spring a trap, make a save or lose HP.

    1. If you telegraph your traps you both train your players to listen to you for clues, which lets you build a language for your game. And you can use them more often without causing your players to become paranoid and obsessively search for traps everywhere, thus slowing down play.

    2. I don't know if it was a game or played or one I watched, but the players were walking around with a ten foot pole poking everything. It. Was. So. Slow.

    3. Ah, "Everything's a Trap" syndrome. It is a DM-induced disease that is a terminal infection for many campaigns, Trying to train my kid out of it at the moment. I have to stab every treasure chest before checking it for traps,

    4. Lol. I tried to do a mimic monster. I straight told them the treasure chest has blinking eyes. They tried to open it anyway. hahah.

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