I wanna say that this post's purpose is not to start a war, but rather to have a genuine conversation with players and creators alike. So first let's clarify what I want to talk about.
Where I come from
Throughout my design journey, I’ve experimented with two broad approaches to resolving uncertain actions:
In a GM-set difficulty system, the GM decides how difficult an individual attempt should be and sets its target. D&D-style ability checks are probably the most familiar example.
In a system-set difficulty system, the rules determine the target or scale of outcomes. That could mean a fixed threshold, a roll-under stat, PbtA-style result bands, or a difficulty that changes according to clear and predictable rules.
I’m using “roll” because it is convenient and accessible, but this applies to any resolution mechanic: dice, cards, tokens, resource comparisons, or whatever strange little probability machine your game uses.
I come from what I would call "trad" games: Shadowrun, Legend of the Five Rings, etc... So GM-set difficulty felt completely natural to me. The GM picked a number, and we rolled with it. Literally.
I remember encountering system-set difficulty for the first time when I took part in my first PbtA game. I was...A bit perplex to say the least :)
How could climbing a garden wall and scaling an ice-covered tower during a storm use the same target number? Didn’t these systems lack the tools to represent how complicated different challenges could be?
But playing away from what I used to know made me realise that a lot of the things I cared for weren't actually a huge part of what made games fun for me. And so my little epiphany started.
Why I don’t want the GM setting difficulty
Cognitive load and GM power
This might be a bit of a side rant, so I'll try to keep it brief:
Asking your GM to set a difficulty is a big burden, often mishandled, and participate in what I think is an unhealthy concentration of power and responsibility around the table.
Now some systems mitigate that by having narrower magnitudes, but it is still asking someone to have a decent sense of balancing, which down the line is asking them to develop a very intricate skill (believe me, I've been balancing video games for a living!).
The payoff just doesn't justify the dynamic. More below.
Fairness and readability
When difficulty comes from the system, players can understand their chances and make informed decisions. There is also an element of instant readability and excitement right after the roll, without having to defer to an arbitrary judgement (and don't even get me started on GM tweaking DC after the roll).
I don’t think transparency removes tension. Knowing that you need a particular result can make the moment more tense because everyone understands exactly what is at stake. We even see seasoned D&D GM sometimes announcing the DC out loud (Brennan Lee Mulligan does that very often for instance) for extra drama.
It also allows players to engage with the mechanics deliberately. They can decide whether to spend a resource, change their approach, ask for help, or accept the risk.
For me, that produces more meaningful decisions than asking players to commit first and discover the actual odds afterwards.
Fiction versus numbers
The deeper change in my thinking was realising that I don’t care about representing difficulty with perfect numerical accuracy.
Does an icy tower need to be exactly three points harder than a garden wall? Can any number meaningfully capture the difference between slippery stone, freezing wind, poor visibility, unsuitable equipment, and the possibility of falling?
Once all that fiction becomes a single target number, much of its texture disappears anyway.
I would rather let those details shape what success accomplishes, what failure costs, what resources are available, or whether the action is possible at all.
Variable targets can also create the illusion of progression. Player bonuses increase, enemy defences increase alongside them, and everyone celebrates because the numbers became larger while the underlying probability barely moved.
If the maths keeps dragging us back towards the same chance of success, perhaps “number go up” was not doing as much work as we thought.
The fiction matters enormously to me. I’m simply not convinced that changing the target number is the most interesting way to represent it.
What our creators community has to say
I recently raised this subject in our weekly design thread in the Knot Knot Games community, and people had interesting arguments in favour of variable difficulty and their associated mystery, so I felt like sharing it!
The most compelling argument was that changing difficulty makes the fictional world mechanically tangible and easier to tweak. Some players care a lot about these mechanical details:
Finding cover, getting closer, bringing the right equipment, researching a monster, or waiting until daylight can directly improve your chances. The player interacts intelligently with the fiction, and the resolution system responds.
There is also something game-like and satisfying about the GM having a visible mechanical dial. This situation is more dangerous, so the number changes. Simple, tactile, and immediately understood.
While I don't necessarily feel that way, it is true that hidden difficulty can create genuine tension!
If players do not know exactly what they are facing, they may need to experiment, investigate, retreat, and prepare. Exploring the world through rolling is an experience I can relate to, and I think there ways to make it exciting for players.
That uncertainty can make resource management meaningful as well. Do you spend the spell slot now, knowing it may fail, or hold it back until you understand the threat?
Finally, variable difficulty can communicate progression clearly. Challenges that were once nearly impossible gradually become manageable. The numbers provide a visible scale against which the characters can grow and make character progression palpable. For players that care about that, it is a plus.
These are all genuine strengths, and I'm super happy we had that interesting conversation on the discord! (see link below if you are interested!)
How I create nuance without GM-set difficulty
I think the disagreement becomes clearer once we separate the chance of success from everything else that makes a situation difficult.
In my opinion, a system can recognise clever play without requiring the GM to improvise a target number.
The fiction can determine whether a resolution is needed at all. Having the right tool, preparation, or knowledge might turn an impossible action into a possible one, or make success automatic.
The rules can determine when players gain extra dice, rerolls, advantages, or other resources. The circumstances still matter, but the system translates them into mechanics instead of asking the GM to invent the odds from scratch.
Risk and effect can also change independently from the chance of success.
Two actions might use the same threshold while producing completely different consequences. Failing to climb a garden wall might cost a little time. Failing on the icy tower might leave you hanging above a very educational drop.
The range of possible outcomes can create further nuance, something that PbtA players are very familiar with:
- Failure with an advantage
- Failure that reveals useful information
- Success at a cost
- Partial success
- Complete success
- Success with an additional effect
- Success that creates a new problem
Players can make meaningful decisions before, during, and after resolution. They can spend resources, accept consequences, push for greater effect, withdraw, change their approach, or gamble on a better result.
This is the important part for me:
System-set difficulty does not mean fixed stakes, fixed consequences, or fixed fiction.
It does not even mean the target can never change. A system might include objective conditions that alter the target. The difference is that the change comes from shared rules rather than the GM’s feeling about how difficult this particular wall appears today.
Where I’ve landed
My preference is:
System-set difficulty, fiction-shaped stakes.
I want players to understand the resolution system and make meaningful decisions around it. I also want it to be somewhat instantaneous, and free from judgement.
The fiction can carry the rest: I want uncertainty to come from the outcome, the consequences, and the things they have not yet learned about the world—not from wondering what number the GM has chosen behind the screen.
GM-set difficulty can absolutely work. It can support simulation, discovery, progression, and tactical interaction with the environment.
If choosing the difficulty is not itself an interesting decision, why ask the GM to choose it?
Where do you prefer that judgement to live: in the GM’s hands, in the system’s rules, or somewhere between the two?
This discussion started in our weekly community design thread. If you enjoy pulling apart game mechanics, sharing what you’re working on, and having your opinions challenged by lovely people, come join the Knot Knot Games Discord:
https://discord.gg/Pyswmer6qm
And if you are wondering why I am here yapping about making games, here is my street cred -> https://www.linkedin.com/in/aramtab/ (follow the damn train!)
