RPG Design Journal #2: ANRPG’s Core Mechanic

For the first post in this series, click here.

Previously, I pontificated on my prefered particulars for an RPG ruleset for Avar Narn. If it’s been a short while since that first post, that’s not because I haven’t been working on the system–it’s because (as intimated in that first post) I spent a good deal of time working on a 3d6 core mechanic. Before returning to a dice pool mechanic.

What I’ve chosen is a d10 dice pool system, not unlike (in several ways, at least) the Storyteller system. Here are the particulars:

(1) A pool will typically be between 1 and 10 dice, with both Attributes and Skills rated between 1 and 5.
(2) The size of the dice pool may be modified up or down, but only by factors inherent to the acting character, such as injury. Dice pools may only exceed 10 when supernatural effects are in play.
(3) The “standard” target number for each die is 8, but this may be modified to 9 for disadvantageous circumstances or to 7 for advantageous ones. Each die meeting or exceeding the target number will count as a “hit.”
(4) Any die that rolls a 10 will count as two “hits.”
(5) The amount of “hits” needed to succeed at a task is called (for now, at least), the Threshold. Threshold is always between 1 and 8, with 1 being easy and 8 being near (but not) impossible. Anything that would be “very easy” isn’t worth rolling for and anything that would be “impossible” shouldn’t be rolled either–as common sense would dictate.

I’ve selected the above rules for the core mechanic in part because I like how the statistics work out. There’s enough granularity for a step up or down in dice to be a palpable change, for advantage/disadvantage to be important but not overwhelming, and steps within Threshold seem to have the right about of change to percentage success as well. It took the addition of rule (4) above to make the statistics work like I wanted to (I think–see previous comments on the importance of the feel of the statistics over the actual statistics). I must credit that idea to the fact that I’ve been reading the Wrath & Glory RPG recently (review on that in the near future).

We need to add a few additional interpretive aspects to the core mechanic to round out its effectiveness.

Particularly, an approach to “failing forward” and “success at cost” as well as a “margin of success” or “failure” in general.

Before any playtesting or development of subsytems, I’m thinking the following: If the roll generates a number of hits that is three or lower than the threshold, the roll is either outright failure or success at a major cost (depending upon consequences and narrative necessities). If the number of hits generated is only one or two lower than the Threshold, this should probably be a success at a minor cost. Remember this must be subject to what makes sense in the narrative. Sometimes it’s good to fail outright. Note also that this means that rolls with a Threshold between one and three are not going to fall into the “success at major cost” under these guidelines. I like to think of this as the “aim small, miss small” principle from The Patriot.

This can be flipped around for degrees of success as well. Reaching the Threshold exactly is success without any additional effect and extra hits can be viewed “success and a side benefit.”

Of course, some subsystems (like combat) will use the hard number of hits generated to determine degree of success or failure.

I’d like to come up with a good way to have the dice give some additional information aside from success or failure–like the “boons” and “banes” of the FFG Warhammer 3rd Edition dice. Using 1’s for negative effects seems a no-brainer, but with 10’s already counting as two hits, I’m not yet sure what I would do to balance for positive happenstance.

One thought I’m toying with is to have some of the dice differently colored (one in the first color, two in the second color and the rest in the “standard” color). This could allow the use of those three dice to be interpreted for particular other information in the roll if appropriate. The set up also allows us always to roll those three dice–if your dice pool is only one or two, you just look to the dice of the appropriate color for counting hits. Not sure if this extra complexity will be worth it, but it’s somethign I’m thinking on.

I’m also heavily leaning toward the idea of “dice bidding.” This mechanic allows the player to sacrifice dice from her pool to be counted as extra degrees of success if she meets the Threshold. It’s a classic risk versus reward mechanic, which I think fits thematically in the grit of Avar Narn.

I’ll be adding a resource to allow characters to purchase successes on rolls when they really need it, more on this to come.

With this core development in place, the next thing I’ll be doing is running an analysis on what kind of developed subsystems I think are necessary to give the game the right focus and feel.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s