Hidden difficulty rolls

The other weekend I GMed the “Wormsign” scenario at a monthly RPG meet-up and its text suggests some hidden difficulty tests in order to preserve some sense of uncertainty and mystery.

What do you think is the rationale behind this suggestion given that if the test succeeds the group will receive momentum and then realize the original difficulty?

Is it to make the group keep guessing the difficulty until someone succeeds in case of a group roll? Is it to make players spend their character’s resources due to the uncertainty?

Thanks for any thoughts on it.

The closest I come to hidden difficulty tests is on information based rolls.
In those cases though it is more a case of variable difficulty rolls, the more successes they get the more information I disclose.

The main part they don’t know is what my maximum intel level is.
So they may get 3 successes and I give them X information, but they don’t know whether if they get another success they may get more or if 3 is the highest level.

Other than that I am pretty open with all my difficulties.


2d20 RPGs handle that by Obtain Information Momentum spends. So you set the Difficulty to D1, or if it is a rather uncommon type of information D2. A success gives the basic information, and each point of Momentum gives additional, and more obscure information.

The difference between Obtain Information Momentum spends and raising the Difficulty is, that on a raised Difficulty failing is much more likely, so the characters will get no information at all. And it prompts players to use resources like Group Momentum or even Determination to even make the higher Difficulty, where they could have used that for the Obtain Momentum spend.

Using the Obtain Momentum spend, the players still don’t know how many additional bits of information are to be had, so they can choose to spend some Momentum or all, which they might need later for other things.

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When I read CountThalim response I also thought of Obtain Information Momentum spends as the better alternative. :slight_smile:

It’s not that the game lacks interesting tools in itself to facilitate its collaborative creative gaming experience… :wink:

In general, the Obtain Information mechanics might work. But I just started reading the Wormsign adventure, and I came across one of these hidden difficulty rolls, and it is a Move roll to land an ornithopter gently enough to avoid attracting a sandworm. So I am not sure how well that mechanic would help in that situation.

The only thing I can think of there is to possibly put off giving the PC’s any momentum for that roll for a little bit, until after they can be sure they succeeded.

Those are actually an exception, and not a good way to mechanically resolve the situation in Wormsign.

(Sometimes, so my impression, the authors of some adventures - Wormsign and the upcoming Conan campaign - are not really familiar with how 2d20 rules work, how resources like Fortune/Determination and Momentum are interacting with the Difficulty of tasks.)

Fair enough. I am curious how you would suggest handling the situation mechanically, then?

Because this is something that happens at times in RPG’s, situations where the PC’s don’t know immediately whether or not they succeeded. And before now, I hadn’t thought of how the Momentum mechanics might make that sort of thing problematic.

I did handle it that way, when I ran this scenario:
Landing is easy: D1
But an easy landing is automatically obvious, anyone could notice that.
So if the PCs want their landing unnoticed, then it is time for some Momentum spends to introduce Traits to the landing like:
“Good Spot”, “Low Impact”, “Muffled Noise” or whatever the players might come up with.
Each of those Traits makes it less likely to be noticed by the smugglers and by the sandworm (and by the opposing house’s troops).
Each Trait costs - as usual - 2 Momentum. So this is expensive, which means, it is time for the group to make this landing procedure a group effort, a few character assisting the actual pilot who takes the lead in this action.


But how do you handle the narrative aspect of the PC’s not knowing whether they succeeded or not, as is often the case in RPG’s where a roll is made to avoid notice. You don’t always know right away if you successfully avoided being seen or heard.

Make it a Contest and don’t show them the worm’s roll. The players can dump as much or as little Momentum into their result as they like, and hope for the best.

EDIT: I just read the Dune rules for Contests (I haven’t played that specific 2d20 ruleset yet) and I see now that it works slightly differently than Struggles or Opposed Rolls in earlier 2d20 systems.

The idea in older systems is that the opponents are rolling against their own Difficulty in a separate-but-parallel roll to your own. They may have a D1 and you may have a D2 to succeed in your action, for example. You tally up the Momentum at the end, and the person with the most wins the Struggle. Thus, if someone has a much easier task in opposing you than you have in attacking them, it’s very difficult for you to win that particular match-up.

I would recommend adopting that mechanic here, or modifying the existing Contest rule to meet the spirit of what I described above.

For example: say the landing is a D2, and the worm has a D1 to Observe it. (Modify those ratios to tweak the actual Difficulty of the Struggle.) Players roll 4 total successes (= 2 Momentum) and choose to invest both of the Momentum generated, just to be safe. Worm rolls four successes as well, which is 3 Momentum, meaning that the worm has won that Struggle (3 > 2). Worm wins, but the players are none the wiser for that until it’s potentially too late. Depending on how you narrate that, they may not even be aware that it was a Struggle, or they could simply not know who precisely they are Struggling against.

What if the PCs had generated more Momentum than the worm? Than they could use that to create a Trait or simply save it in the group Momentum pool.

2d20 assumes that all mechanical things are on the table, upfront, obvious to the players, so that they can make decisions from the director’s stance, not the viewpoint of their characters.
That is a thing 2d20 has in common with all those meta-game-heavy systems like Fate, Cortex Prime, etc.

Hidden rolls, hidden outcomes or even hiding that there was a skill test in the first place, that is more a D&D-like thing, not a 2d20-like use of mechanics.

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Totally agree, and we have this convo a lot at my table … 2d20, generally speaking, isn’t meant to be a simulator, it’s meant to play more like a boardgame insofar as everything is, as you say, on the table. If you are the kind of player who hates it when a roll tells you that you have to be a sucker, then you may need to adjust your expectations or home-brew some stuff.

As for your comment about gaining more Momentum than the worm making them aware that there was a Struggle, that’s true. And yeah, you’d still have to give the players the Momentum when they won. But, the OP was concerned with the players surmising the Difficulty of the check somehow, and this could maintain that “black box,” at least, in the instances where the players do succeed. Because, even then, as the player receiving the 1 Momentum (from the earlier straw man), you only know that your total Momentum was more than theirs, however, you cannot deduce the Difficulty of the opposing roll with just that information.

An imperfect solution, to be sure, but I can say from experience that in those instances where the players don’t want to know (because it’s more fun for one reason or another), it’s a framework that requires very little editing to RAW and isn’t complicated.

Thank you Maxspire, that was very helpful.

I have never played Fate or Cortex Prime. I remember beginning to read Fate, and something I read (I don’t recall what, it has been a while) put me off of the game, so I didn’t even finish the read-through of the rulebook.

Dune 2d20 is mechanically currently the closest one to Fate in the whole 2d20 RPG family.
Mutant Chronicles and Infinity run much more like “conventional” RPGs, Dune, Dishonored and to a greater part Star Trek Adventures are quite close to how Fate works.
As a long time Fate and Cortex Plus / Prime player those similarities were actually an advantage, because we in our groups “got it” right away. And I have to say I do prefer 2d20 dice mechanics in a Fate-like system to the FUDGE dice Fate uses.

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Sorry to be late to this one, but I should clarify.

Where it says ‘don’t tell them the difficulty’ that doesn’t mean always keep it a secret forever.
The PCs will know how well they did after the test. They just don’t know what the difficulty is before the test.

In this way, they are in the dark about how hard it will be, and so will find it hard to gauge what momentum etc to spend on the test. But once the roll is made the GM can reveal ‘you only needed X’ or ‘good thing you spend a lot of momentum as the difficulty was X’ and move on from there.


So to clarify Andy, they make the roll and decide how much momentum to spend on succeeding before the difficulty is revealed?

Yup, for some of the rolls, not as a general rule.
Basically, some challenges are harder to gauge for the characters so the gm can keep the difficulty secret until after the dice result, forcing the players to take more risk with momentum spends.

I’ve been mulling over this since last week, and I think the issue here is not so much keeping the difficulty secret so that players potentially “overshoot” what they needed to succeed. Rather it is a situation where the players don’t know if they succeeded or failed until later in the story.

The problem is that they expect to be given momentum if they succeed at a task, so (in this adventure) when they try to do a “stealthy” landing, and don’t get given any momentum, they know they’ve mucked things up, and can expect trouble further down the road (which their characters shouldn’t know).

Perhaps the slick way to adjudicate this is to realise that threat points are worth the same as momentum points. Hence the GM could openly treat the task as a difficulty 0 task, giving the players 1 momentum for each success they muster up. Thus at the time of the landing, the players simply get rewarded for doing a good job, and have no idea that they’ve actually failed.

If the players get less than 4 successes (they fail), the GM takes 1 threat for each success they earned. Effectively, the amount of GM threat balances the player momentum, equivalent to the players having earned no momentum.

Alternatively, if the players get 4 or more successes, the GM just takes 4 threat. For example, if they got 5 successes, they get 5 momentum, but the GM gets 4, which is equivalent to giving them 1 momentum (with no threat): the reward they would have received if rolling openly against a difficulty 4 task.

This way, the momentum/threat rewards stay balanced as if the task was done openly, but the players don’t know that they’ve actually failed at the task based on not receiving momentum.


My take on this would be to consider what the Momentum really represents in-game. A sort of satisfaction and level of confidence? I think it’s OK in very rare cases, like where the characters should not know for certain if their Stealth was successful enough, or whether their attempt to bypass the silent alarm worked, then the Player doesn’t get the Momentum until they eventually find out (when the character gets to feel smug about it!).
As an alternative, you could ask them whether they think that’s a good enough result “What do you think the Difficulty probably was?” and give them Momentum based on that number. It’s open to a bit of abuse, but Dune Players are a cut above average role-players, aren’t they?

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I do the same sometimes, its a good plan to keep them on their toes.
You could even go as far as to keep the amount of momentum they have hidden and just ask them if they want to spend it, just saying no if they don’t have enough. :slight_smile: