Compromising Cairn

14 Jan, 2026

I love the Into the Odd / "Oddlike" / "Mark of the Odd" design space, these games feel natural to referee, they are "rules light" but the rules are highly impactful on play, they leave blank spaces in ways that invite the referee and players to be creative, and they play fast at the table.

Mausritter and Mythic Bastionland have been sources of delight for me as a referee, and Cairn 2e is going to be my preferred way to run a classic DungeonDragon-ish fantasy elfgame for the foreseeable future.

That said... there's two potential issues which stand out to me in terms of presenting Cairn to prospective players (who may have certain expectations when it comes to their Dungeon or Dragon type play experience):

the Cairn 2e player Backgrounds are not directly replicating the familiar “iconic” classes of old school or modern Official Brand D&D.
the absence of formal and mechanical "number go up" incentive and reward (i.e. no traditional leveling system).

The first point has already been solved by other people, better than I could do it, through the reworking of classical D&D-style classes and origins as Cairn 2e Backgrounds:

So we take the Backgrounds from either or both, include them in our home game. Great start.

Alternatively we could use the Trad Fantasy Ancestries for Cairn by Meatcastle Gameware hack in combination with the Backgrounds from the Cairn 2e Player's Guide, as another way of creating a similarly recognisable D&D-ish offering on the player side of the table.

Which brings us to the incentives, leveling, "number go up" part. I know what you're thinking - I'm thinking it too:

why ruin Cairn's elegance?
surely there's nothing wrong with diagetic and inventory-based character progression?
should we really add mechanical incentives? Isn't play and discovery its own reward?

Well... the title of this post is Compromising Cairn and we're looking at how we could bring this game a little closer to the expectations of people who might otherwise ask me to play an Official Brand Product or an old school retro-clone... so we're adding in Levels. Many people (incorrectly) believe that doing a Dee-an-Dee requires that you get to be a Level 3 Fighter, Mage or Vicar so here's a way to dangle that carrot.

There's an added upside to Levels in terms of baking-in some additional resilience for player-characters of a long form campaign game, but the goal shouldn't be to break Cairn's lethality.

Making the numbers go up

Gold for XP, XP for gold. That's the old school, baby. It's an incentive structure that fits, I can't spill better ink on this issue than more esteemed bloggers and designers already have.

We're going to borrow liberally from Mausritter here, with some slight adjustments, as well as swiping and modifying some of the combat components of Mythic Bastionland.

Some establishing guidelines:

The highest Level is 5. Any "progression" after that should come from the rules and principles established in Cairn 2e. Players who survive to Level 5 using this hack should be mechanically powerful, relatively speaking, but not unkillable. If players want more power they should look to their Relics, domain level play, social power, Scars, and Growth within the fiction as described in the Cairn rules.
Advancement/progression choices made by the players should be considered in light of what their character has accomplished or attempted within the fiction. Someone who has never attempted to cast a Spell should consider alternatives to "Known Spell"; ditto "Two Weapon Fighting".

Okay, it's hacking time. What follows is rules text...

Level Procedure

For every new Gold Piece (GP) or GP worth of treasure brought to the safety of a settlement by the party (divided equally among the party) your character earns 1 Experience Point (XP). You can earn additional XP by spending GP in a settlement; for every 10 GP spent in this way your character earns 1 XP.

When your character earns enough XP to advance to each Level, use the following procedure:

Roll for Attribute increase: roll d20 once for each of your character’s STR, DEX and WIL. If a result is higher than the Attribute’s current value, increase it by one. This cannot raise an attribute score above 15.
Roll Hit Dice: roll the dice listed for the new Level’s Hit Dice in the Level Table below. If the value is higher than your character’s current HP, replace your HP with the rolled value. Otherwise, increase your character’s HP by 1.
Choose one Advancement for your character from the Advancement table below, to a maximum of the number listed for your new level.

Level Table

Level	Hit Dice	Advancement	Experience Points
1	1d6	0	0
2	2d6	1	1000
3	3d6	2	3000
4	3d6	3	6000
5	3d6	3	11000

Advancement Table

Name	Effect
Known Spell	Destroy a Spellbook your character possesses and note the spell name and the following text on your character sheet: You may now cast this spell from memory, adding Fatigue to your inventory as normal; casting a Known Spell has the same potential risks, costs or drawbacks as casting from a Spellbook or Scroll.
Smite	Note the following on your sheet: Before your Attack roll you may add Fatigue to your inventory, then for this round either your Attack die is increased to d12 or your Attack gains Blast.
Deny	Note the following on your sheet: After an Attack roll against you or an ally within arm’s reach you may add Fatigue to your inventory and discard one Attack die from the roll.
Bolster	Note the following on your sheet: If attacking the same foe as another character and your Attack die is not the highest result, add +1 to the Damage inflicted to the foe.
Two Weapon Fighting	Note the following on your sheet: If attacking with two weapons at the same time, roll both damage dice and keep the single highest result then add +1 to the result.
Alacrity	Note the following on your sheet: If in Combat, after your Attack you may add Fatigue to your inventory to make an additional Move up to 40ft.
Duelist	Note the following on your sheet: If fighting a single humanoid opponent alone, add +1 to the result of your highest Attack die.
Sharpshooter	Note the following on your sheet: If using a ranged weapon in combat and you haven't moved this turn, add +1 to the result of your highest Attack die.
Pack Rat	Add an additional Inventory slot to your character sheet; this new slot follows the same rules as the rest of your character’s inventory.

Players should be aware that casting a Known Spell without the aid of a spellbook is a remarkable act and can attract unwanted attention. Additionally, the Warden consider whether the player's character should take on some of the physical properties or drawbacks of the destroyed spellbook.

It is more important for a character to become more interesting than to become more skilled or capable [...] Characters may change in a way that they don’t like or may gain new abilities at a cost.

Cairn 2e Warden's Guide: Growth by Yochai Gal

Further Self-Justification and Explanations

Why stop at 3 Advancements per character?

Damn, how powerful do you want your players to get? This limit should drive the players to make well-considered choices and help to keep each player character in the party feeling distinct.

Why not classes, again?

Having a common Level Procedure for all characters is easier and I’m lazy. It maintains the existing Cairn framing of Backgrounds being how a player starts out, and any character growth that occurs thereafter is a result of player agency and what happens within your game's established fiction.

Why does Level 4 and 5 look the same in the Level Table? Why cap the stat increases at 15?

I feel like 18 HP and three attempts to get that high is plenty. We're trying to bend Cairn into more of a B/X shape, not break it.

The same applies to capping the Attribute increases from Levels to 15 - that's a 75% chance of success on Saves for Attributes that haven't been depleted. Within the fiction you could justify this by saying that it takes a lot of effort just to maintain that level of high performance, relative to an ordinary person (8 to 10 being average/normal for humans).

I still want to leave space for increases from Scars. If players improve their stats above Level Procedure numbers through Scars then they've earned it fair and square.

Can I ignore parts of the Level Procedure?

Please do! Treat it as modular. Carve bits off, ignore the things you don't like or have a use for, use the Advancements as examples of diagetic Growth you can import into your Cairn game, etc.

Cairn is already a fork of Into the Odd for doing the D&D thing, why are you messing with this game to cater for people who don’t get it?

I’ve seen enough comments and concerns from GMs and potential players on various social platforms about the lack of mechanised “character progression” to believe there’s some value in this hack.

While I fully agree with Cairn's principles and Yochai Gal’s design intent regarding diagetic character progression/growth (his way is surely the preferable way to play this game), I’d rather lure people off the fence for a game of Compromised Cairn than compromise my own preferences as referee (by using a retroclone or official brand D&D edition). I’m selfish like that.

Why use 'Bolster' style +1 effects instead of rolling additional damage dice?

I think it combines cleanly with existing rules of the game like the 'Enhanced' and 'Impaired' effects, while not pushing the power level of the players too far. It shouldn't get too messy if the players find a magic sword that has an additional Attack die over the standard Marketplace examples. The +1 is still pretty significant in a game where numbers are low, you're usually rolling one die and a lot of foes have an Armour value of 1 or 2.

Why not import all of the Mythic Bastionland combat rules?

I don’t think it’s as simple as a grab-and-go compatible port from one game to the other. Mythic Bastionland is about capital-K Knights, doing knightly things, and Cairn is about grimy weirdos in perilous forests and dirty dungeons. The way they fight should feel different.

There are subtle divergences in the combat math between these two games - not least the Attack dice values listed for various weapons - and I believe it’s preferable to bend the Mythic components to fit the Cairn hack than to distort the Cairn chassis around the Mythic bits we’re adding in.

Some of the Gambits in Mythic are explicitly mechanising actions a character could already perform (instead of an attack) in Cairn via player-led creativity and fictional positioning, and tying that action to a die result - bearing in mind that the Cairn player is probably rolling fewer dice.

Much as I dearly love Mythic its combat resolution is a little slower and more considered than that of Cairn (albeit much faster than most other games), so there's value in keeping Cairn's fights more frantic.

Citations & References:

see also: Citations & Inspirations