The D8

Chronicles of darkness uses a core resolution engine of Attribute+Skill+Modifiers to determine a dice pool of d10s. This pool is rolled and a success is achieved with a single hit of a 8,9 or 10 on the dice. Exceptional successes with five instances of a hit;  the effects of an exceptional success varying  depending on the action.  

Overall I’m very fond of the core resolution mechanic within chronicles.  One thing that I have noticed within the playerbase of the system is a constant creeping of how comfortable players feel with a dice pool of any given size.  The average for comfort seems to start at around 6 dice-this is a problem as Chronicles assumes that a stat of 3 is a very skilled pro while an attribute of 3 is above average.

Here are the percentage chances of a simple success on a d10

1d10	30%
2d10	51%
3d10	65%
4d10	75%
5d10	83%
6d10	88%
7d10	91%
8d10	94%
9d10	95%
10d10	97%

So if players feel actually comfortable with any given roll once they have 6 dice that means, the satisfaction with success rate is 88%  This makes sense to me, as humans like to win and they like to see their character succeed. However this percentage clashes with how people tend to view trained professionals and their success rate in real life, especially when you take into account that in most situations you’d be dealing with some amount of negative modifiers.

Now I actually think that lower success rates make sense in a game designed to be a horror game. Characters are supposed to feel more powerless and as if they have to struggle to survive.  However I do reject the notion that mechanics such as this are required to run a horror game and that such a game can be captured by vibes and story telling.

On the flip side I do think that non horror games fundamentally benefit from increased odds. Thus the Vapor System will use a D8.

1d8	37.50%
2d8	60.94%
3d8	75.59%
4d8	84.74%
5d8	90.46%
6d8	94.04%
7d8	96.28%
8d8	97.67%
9d8	98.54%
10d8	99.09%

As this chart shows, an average professional in a skill/career  would then have a 84% chance of success. This should once felt in practice mitigate concept dice creep 

Dice pool modifiers

Chronicles uses several dice tricks to modify dice rolls. The basic ones being 10 again,9-again, 8 again and rote. There’s also advanced action and various tools that change the threshold for exceptional. Vapor will simplify these slightly but generally they are the same.

Vapor will use the following dice tricks:

8 again: When an 8 is rolled,it hits and then you reroll the die.

7 again: when a 7 is rolled, it hits and then you  reroll the die.

6 again: when a 6 is rolled, it hits and then you  reroll the die.

Rote: Reroll all dice that failed once.

Exceptional thresholds: these change how many hits you need to make an action be exceptional.

This will likely depend on setting but rote should generally only be earned for specific tasks related to a character concept. Exceptional thresholds likely being reserved as of the many benefits a race or sub race might have.

Due to the increased probabilities of d8s, the dice tricks are likely less needed in general. 

Critical failures

Exceptional failures or critical failures are an example in my opinion of a mechanic that has existed in games simply because it’s always existed.  I could see how they exist to allow opportunities to create drama. This is particularly important in Chronicles where the world is a terrible place and part of the drama of the game is dealing with terrible things.

I don’t want sources of artificial drama in the vapor system. It usually leads to either slap-stick or terrible consequences that snowball out of control randomly. I think all failures should be natural to the scene and realistic within the narrative.

That said, exceptional successes are still in the game. Its good when player characters succeed.

Dice limit

Chronicles theoretically has a maximum dice pool size due to the limits on Attributes and skills. In addition it does have a rule where modifiers add or subtract  more than 5 dice. However there are 3 or 4 interpretations of that rule among the player-base, a few of them inflating dice pool sizes to insane numbers. 

To fix this, Vapor has a 25 dice maximum pool size- this represents whatever the godly peak of reality within whatever setting it occurs in. Additionally penalties are applied after all bonuses are applied in all circumstances with the exception of willpower which is applied after penalties. This means that the absolute maximum dice pool for a task that has no negative penalties associated with it is 28 dice.

You can use the mnemonic “Allen steals bones pleasing william” to help remember.

We have talked about the Dice we will be using- the D8. Next we need to talk about when that dice will be rolled- this will be covered in two chapters. The first discussing skills and attribute checks. The second discussing combat.