Variable Difficulty, or How I Learned To Love The X-In-6

None of this is groundbreaking, but it’s sometimes handy to describe one’s internal goings on, especially if my future self needs to look back at me with a slightly quizzical expression.

We’re coming up to a year of playing through Greg Gillespie’s Barrowmaze using various versions of Off-White Cube. Whilst classes have come and gone, and leftover remnants of mechanics inspired by older games have been pruned, throughout it all OWC has clung to its basic task resolution: roll a d6, add appropriate modifiers and aim for a 6 or better, a natural 6 always succeeding.

Largely influenced by Knave‘s ’15+ on a d20’, this mechanic made things nice and easy to explain to new players and was simple to remember.

However, it never seemed to be quite right in my mind. The lack of granularity didn’t always work, and I ended up including a note saying that +1 could be added for an ‘easier’ challenge. Now a player could potentially find themselves adding several different bonuses from attributes and abilities, which either slowed down resolution or risked them forgetting something (and when each +1 is a 16.66% increase in odds, every bonus counts). This wasn’t satisfactory.

It couldn’t be made any harder if a natural 6 always succeeded. Negative attributes never actually came into play unless the character already had a class-based bonus. Not ideal. (And I discovered that I really didn’t like players having to add and then subtract modifiers for the same roll.)

So I’m turning to x-in-6, often used in earlier editions of D&D to resolve many non-combat-related tasks but largely dropped in favour of a d20-based attribute roll.

I find the small range of results on a d6 much easier to mentally filter into probabilities – a GM is less likely to waver between target numbers compared to the 5% increments on a d20 – while still allowing there to be a significant variety of challenge difficulties.

Traditionally the x-in-6 would indicate that someone needed to roll x or under on a d6 to succeed, but I come from a board gaming and miniature gaming mindset where higher is better, so OWC flips the equation to rolling over a number.

• The majority of challenges should be a 5+. It’s an achievable roll, but tricky enough that it’s not a good idea to find yourself making too many of them. If in doubt, go with 5+.
• If it’s harder than a standard challenge but possible, it’s a 6+.
• If it’s easier than a standard challenge but not one a character can do casually, it’s a 3+.
• If it’s a straightforward but something could go spectacularly, interesting and / or entertainingly wrong, it’s a 2+.
• If you have no idea whether a task would be easy or not, it’s a 4+.

Those parameters are simple enough that an easily overwhelmed head like mine can still retain them, but give a bit more in the way of granularity. There’s a standard go-to challenge roll, and adjustment either way for notably easier / harder tasks, and then some rarer outliers. On the basis that dice are only being rolled if there is a prospect of success / failure, an automatic success or failure on a 6 or 1 respectively means that there is still a decent chance of either.

I am a visual fellow – if I’m presented with a game rulebook, I grock its concepts a lot faster if they’re presented with diagrams and flowcharts. With that in mind, here’s a process by which someone brand new to the concept of a x-in-6 odds could get an idea of how to adjudicate target numbers:

For those who prefer things in table form:

Likelihood for a standard person	Odds of success	Target number
An impresive feat	1 in 6	6+
Tricky, but not wildly optimistic to expect success	2 in 6 or 1 in 3	5+
No more likely to fail than to succeed	3 in 6 or 1 in 2	4+
Most could expect to do this, but it’s not easy	4 in 6 or 2 in 3	3+
Very probable, though there is chance something could go spectacularly wrong	5 in 6	2+

I am also toying with the idea of removing any bonuses / penalties to these rolls other than attributes so as to make it as simple a roll as possible: roll a d6, add a single modifier and aim for the target number or better. But that’s probably for another post.