The Art of Conversion
Introduction
I have said on more than one occasion that Gus L.'s Crystal Frontier is my favorite published setting, and Cairn is my favorite game, so it is only natural that I would want to combine these two things that I love. This led me to convert several Crystal Frontier adventures:
In the process, I have a few thoughts I'd like to share about the art of converting a module from one system to another. This can be a challenging proposition, even when converting to a system like Cairn that was specifically designed to let you run old school modules using it. I also want to talk about common issues that arise when people are discussing rulings that commonly come up in more traditional adventure games, and how I think they are best resolved using the existing rules and principles of Cairn.
I will be using examples from Crystal Frontier modules in this blog post. As always, if you're ever planning on playing in a game that uses Crystal Frontier stuff, it might be wise to steer clear of this post until that happens.
Statblock Distillation
When most people think of converting modules, they think of Statblock conversion. Modules made for OSE make this tricky because they are generally not concerned with attributes. Yochai Gal, the creator of Cairn, has a great conversion guide here. All of the advice is useful, though I will say that I'm very much in the "Use the Fiction" camp over determining attributes based on saving throws. There are a few additional things that cropped up often enough that I wanted to talk about my experience with them.
Morale
Morale is one of the things in Cairn that has been simplified: Instead of being a separate statistic, NPCs in Cairn must make a Willpower save or flee. The current conversion advice suggests that the higher the Morale score, the higher the Willpower score. This mostly works except for in the case of things that have animal-level intelligence. You'll end up with a monster that can't be easily lured away or tricked because of its iron will.
My solution was to create abilities to assign to certain opponents who would normally have a high Morale, but assigning them a high Willpower doesn't make sense with the Fiction. For example:
Glass spiders have a WIL of 6, which feels right given that they are animals and PCs should be able to trick them by exploiting their instincts. However, they also have a Morale score of 10 in Gus's Module, so they aren't meant to be frightened away easily. Converting using Yochai's guide would give them a WIL of 15(!), making them very difficult to trick outside combat. This doesn't really make sense within the Fiction, as they aren't rational, hyper-disciplined opponents, so my solution is the following ability:
Tenacious: Glass spiders do not check Morale (WIL save) unless reduced to 0 HP or faced with overwhelming force.
Of course, this is only my official solution. My actual solution is simply to keep Morale separate from Willpower (Don't tell Yochai).
Movement Rate and Dexterity
Something that Yochai alludes to in his Converting Monsters advice that I think is worth calling out is how a creature's Movement Rate can be used to determine its Dexterity Score. It doesn't really work with humans and the like, but with everything else the higher the Movement Rate the more you can adjust the Dexterity score upward.
Not only is this helpful in general sense of knowing how clumsy/agile something is, but it also keeps things compatible with old school sensibilities due to the fact that DEX saves are used to determine if something can successfully retreat.
For example, the Bearowl in Tomb Robbers has a Movement of 90(30), which is fast enough to catch any character that has any sort of movement restriction due to armor or encumbrance. It's also, essentially, a bear, so it should be pretty damn fast. I gave it a DEX of 14 as a result.
Touch Attacks and Poison
One of the most challenging aspects of converting B/X monsters to Cairn is poison and what I think of as Touch attacks (I'm showing my 3rd edition roots). I see people stumble on this aspect of Cairn a lot, so let me unpack what I mean. In Cairn there are no attack rolls. You simply roll damage, apply the result to Hit Protection (after subtracting your Armor score), and transferring any damage left over after HP is gone to STR (which will provoke a Critical Damage save). Effectively, this means that until HP is gone, no meaningful hit has taken place.
For Monsters that inflict poison attacks, like the infamous Glass Spiders from Gus's Crystal Frontier adventures, this means that you don't have to worry about their poison until you fail a Critical Damage save. The save is effectively performing double duty, determining if the creature's attack overwhelms your defenses and if you succumb to its poison.
Art by Gus L.
On the surface this seems like a major shift in how monsters like the Glass Spider operate, but in reality there is little difference between a B/X monster with a negative attack modifier (or high THACO, for you purists) and a Cairn Monster that only does something nasty to you if you fail a Critical Damage save.
A similar type of ability that is tricky to convert is what I think of as a Touch attack. Mechanically, it is the same as a poison attack but Fictionally all that is happening is that the Monster in question manages to touch a PC. If we were talking about a traditional Ghoul (see below) it could be resolved mechanically much like the Glass Spider above (Save vs Paralysis maps to Strength quite nicely), but the issue lies in if the effect should target something like Willpower.
Traditional Ghoul. Art by LadyofHats. Licensed under CC0.
A lot of people have a tendency to think that DEX saves and the like are a good solution here, but generally with combat there's no need because ultimately the question here is "can a PC avoid being touched by the Monster?" and that is already what is happening when you roll damage and subtract HP. Here's how I resolved it with a reskinned Ghoul in one of Gus's modules called the Revenant of Greed.
Lure of Gold: The Revenant can forgo dealing STR damage, instead grasping the target and provoking a WIL save. Failure results in the victim being overcome with the compulsion to kill and rob one’s companions: They must attack their nearest ally for the next 1d6 Rounds.
For a sufficiently nasty creature that can do things at range, you can give them abilities that deal attribute damage directly (with something nasty happening at 0) and/or a terrible effect with no save, as the illustrious Chris McDowall goes over in this blog post (that everyone who runs ITO-descended games should read).
Traps
Some traps are living... Art by Gus L.
Traps are another common area that I think conversions stumble on, because in Cairn most traps are going to do ability score damage and not HP (unless the trap is a swinging blade that someone could reasonably react to and dodge/parry, but most traps are cooler than that). Because ability score damage is rather difficult to recover in Cairn (unlike HP), traps can (and should) be a serious threat to PC survival.
As a result, it is incredibly important to Telegraph Danger when converting traps from old school modules to Cairn. The best traps in modules do this explicitly, though sometimes you have to extrapolate based on implied characteristics (might I recommend ktrey's excellent A Hundred Clues & Tells for the Tersely Detailed Trap for such times?)
Another thing to keep in mind is that, because traps should be well-telegraphed, they don't necessarily warrant a Save depending on how they work in the Fiction. Sometimes, a person setting a trap off is too close to effectively be granted a Save, but that might not be true of those who are further away from the source of the danger. Crystal Frontier traps tend to be well-telegraphed, but also quite deadly to the unobservant and incautious. This is one of the reasons I found doing the conversions so rewarding.
For example, there is a room in Tomb Robbers that has a trap that will kill you on the spot. Gus has it really well-telegraphed in the description of the room, but lately I've found it useful to create a separate Telegraph Danger section where I specifically call out information you must give to your PCs if you're sticking with Cairn's philosophy on Information (and Into the Odd before it). Like so:
Telegraph danger: emphasize the prisms on the ceiling flaring with white light and beginning to hum when someone steps on the threshold of the room.
It should be really obvious to PCs that it is a really bad idea to enter the room without figuring out what the hell the glowing, humming prisms are about. The incautious get a DEX save, but failure means they are very dead. Which is okay because it was earned.
In general, Cairn removes some of the granularity of traps (there's no roll to see if a trap activates, for instance), but also never trivializes them (because Cairn is Levelless, and Traps generally do straight attribute damage, they never become a HP tax like you see in games where PC hitpoints balloon at mid to high levels). Traps are always a potential threat to PCs, but also a potential resource to exploit in a Combat as War scenario. This, to me, is as it should be.
Multi-part traps are tricky, especially things that require multiple saves or checks, because it starts to work against the clear resolution that a Save in Cairn provides the PCs and Warden. Probably the most challenging trap I have converted is in Broken Bastion, my favorite of Gus's smaller Crystal Frontier adventures. In one room, giant coolant tanks that are unstable and insufficiently patched sit waiting for PCs to tinker with them. If they are foolish enough to do so, PCs must Save v. Paralysis or suffer 1d6 points of damage, and anyone who fails has to make an additional Strength check to regain their footing (+1d6 damage for every round they fail to do so).
My solution was to lean on the Fictional Positioning of PCs. Those who are too close to the tanks when they rupture do not even get a Save, immediately suffering d6 STR damage (not HP. You can't block or avoid acid engulfing you under normal circumstances). Those who are far enough away are entitled to a DEX Save.
These are all subject to Warden discretion, of course. You might give a PC that is too close a Save if they have some means of repelling the acid such as special clothing designed for such a purpose, or even let PCs that are further away avoid the save entirely if they have similar advantages.
Striking a Balance Between Module and System
A few months back, a very interesting question came up on the episode of Between Two Cairns that dealt with Hideo's World and The Haunting of Ypsilon 14 (at 23:17, to be precise). Essentially, the question revolved around if should you Telegraph Danger in a module that wasn't written to do so, because if the designer wanted such a thing to happen surely they would have written it to communicate that. Brad Kerr, one of the hosts of the show, uncharacteristically dropped his Funny/Wise Guy persona to wax philosophical about the fallacy of authorial intent. Honestly, Gentle Reader, you should really just go listen to it (you do listen to B2C, right?), but I will briefly summarize his statements because I found them interesting and relevant.
- You don't owe the module writer anything as far as being faithful to their vision.
- It is good to try and capture the spirit of the module, but you should feel free to twist it to your purposes.
- Even if you wanted to capture the author's intent and run a module exactly as intended, this is impossible unless you are the author in question.
I ultimately agree with Brad here for the most part, though I do think that a module conversion will work best when you can capture the spirit or essence of a module and align it with the parts of the System (in this case, Cairn) that synergize with it the best. This is a lot easier with some modules than others.
What is Owed to the Module?
Gus's adventures are "Classical", site-based adventures that are very firmly rooted in the Dungeon tier of play. They share a lot of characteristics with the older style TSR modules (and newer OSR modules that try to emulate them) that Cairn was designed to run, and so were good candidates for conversion as a result. When trying to capture the spirit of these modules, my priority was to ensure that the challenges and rewards that the modules have in place are not compromised. I think, as much as you can, someone writing a conversion should try and capture the "feel" of the adventure and ensure that difficult obstacles aren't trivialized and rewards aren't watered down.
For instance, one of my big struggles with Monster conversion was making sure that enemies wouldn't break and run too early in Cairn compared to their B/X counterparts. By creating custom monster abilities that modify how Morale works for them, I solved the problem without damaging the Fiction by creating high WIL animals. Things like Glass Spiders remain a viable threat, but they are also potentially dealt with outside of combat by forcing them into positions where they have to make WIL saves.
What is Owed to the System?
Cairn has a lot of philosophical underpinnings that people who have a background in more traditional systems often don't grok at first. A big problem I see with some conversions is that people begin to convert their favorite module before they really understand Cairn, and so you get things like traps doing HP damage and unconverted magical weapons. Ultimately, a conversion should align the module to the system so that you minimize the amount of rulings a Warden has to make on the fly. A conversion that bends the rules of the system too much has entered Hack territory, and so should stay in a Warden's notes rather than published on the Cairn website.
My biggest challenge in adhering to Cairn as a system came when I had to convert a spellbook found in Tomb Robbers full of a plethora of spells of varying degrees of power. Cairn's spells are Levelless, and a Spellbook takes up one slot. Giving PCs a Spellbook with 10+ spells was obviously not an option, but neither was having a whole library of spells on a single person. My solution, after receiving some good advice from Xenio, was to make each spell count as a Scroll that would be expended forever after one use unless PCs took the time and paid the money to research the spell and convert it into a usable Spellbook. A solution that stuck to the mechanics of Cairn while also providing the potential for diegetic advancement.
Going Beyond Conversion
They say that good translators are like good editors, in that their work (properly done) is invisible. You only notice the lack of a good editor/translator. If the same is true of conversion, that I suspect I am not the best. The problem, you see, is that a strict conversion means sometimes leaving out ideas that would work really well with your system, but are well beyond the author's intent with the module.
I'm guilty of this when writing Critical Damage effects for Monsters, as sometimes I think of things that are interesting and lean into the type of complications that I think good Critical Damage effects should occasionally cause. For instance, here's one that I made for Rolling Calf, an undead assassin who specializes in killing rogue magic users:
Critical Damage: The victim suffers 1d6 WIL damage and is left with a brand in the shape of a bull’s skull that, if they survive, will allow Rolling Calf to track the victim wherever they go.
It probably won't matter, but might result in an interesting complication if PCs tussle with Rolling Calf and don't defeat him.
Another one I did for an Empyrean (Space-Elf) Sorceress works like this:
Critical Damage: Arcane energies transform the victim into a statue of Tomb Crystal, their soul separated from their body and vulnerable to torment.
This was originally a spell in her spellbook (and still is if the PCs get their hands on it), but it works great as a method of causing a complication that PCs have to try and decide if they want to resolve. A PC that is killed isn't much of a dilemma, but one transformed into a statue and capable of being tormented is a potential call to action.
In general, I try to restrain myself from doing these things too much, but if you are converting for personal use I would strongly urge you to lean into the strengths of Cairn and ask yourself the following questions:
- Are there any monsters that could have Critical Damage effects that create complications or honor the threat level the monster should be?
- Do the PCs have sufficient reason to even be here? What Relics, Spellbooks, or Items are worth braving the dangers of the Dungeon you are running? If they aren't there, you better insert them.
- Are there any existing elements that act as opportunities for Foreground Growth or advancement that can happen diegetically? If not, what elements could be tweaked to act in such a manner?
Alright. That's all I've got. I still technically have Common Grave (the small dungeon Gus did for the POD release of Tomb Robbers) left to convert, so I should probably get on that.
Wait, does this mean that Crystal Frontier modules are Cairn modules now? If so, I guess I have some items to add to my Review pile...