Mechanic: Craps

[Eddy Fate]

I've been bouncing around a modern day mobster RPG for a few weeks now.  I was trying for some sort of resolution mechanic that is quick, relatively balanced, and evokes "feel", and so for the past week I've been kicking around the idea of using a craps-style die mechanic for the game.

There are only two character mechanics that are relevant to this discussion:

1) The average "trait" for a character is 0, so there's no need for character to note something that they are average at.  Positive or negative traits simply add to the dice roll.

2) Each character has a "Point", which is one of the "hard" numbers in craps: 4 (2 & 2), 6 (3 & 3), 8 (4 & 4), and 10 (5 & 5).

The die mechanic is simple at it's core - roll 2d6, 7 or better wins.  There are two modifications to this, though:

A) Rolling your Point gives you a chip.

B) Rolling a natural seven (seven on the dice, not after modifiers) is always a failure, and you "crap out".  Spending a chip cancel out the "crap out", allowing the seven to count normally as a roll (and probably a success, given the odds).

This skew the mechanic (without chips) for an average roll to 41.6% success, 58.2% failure for an average person doing an average thing.  It's a bit low, but since it's a dark game, I'm pretty comfortable with that.  The chips increased the chances of success, but it becomes a player resource - they decide what rolls are important (and the theme of the game is "choices", so this ties in well).

I am also envisioning an optional gambling rule, where people can place bets with their chips on other player's rolls (on their Point or on Natural Seven) to attempt to gain more chips.

I'd like some honest and constructive feedback.

[Walt Freitag]

Hi Eddy,

Are you saying that rolling the points have to be hardway rolls? The odds are 1 in 36 for all such rolls. This wouldn't put many chips in play. (On average, only one in every six rolls of 7 could be reversed by using a chip.)

You could allow all the craps points, 4, 5, 6, 8, 9, 10, and allow them to be rolled any way, as in craps. The odds are different for different points, of course (1/12 for 4 and 10, 1/9 for 5 and 9, 5/36 for 6 and 8), so you could use shifting of the points as a mechanism. At 4 and 10, you get on average enough chips to make half your sevens into successes, and things get better from there. (If that's too generous, require two chips to reverse a 7 roll).

If only hardway rolls count for Points, I see a problem with betting on other players' Point rolls. The odds are so steep that you'd have to offer a big payoff (at least 30 to 1, which is the sucker bet most casinos offer) to make it worthwhile, and that could really skew things if a bet pays off. Regular any-way point rolls with better odds would be easier to manage.

As written, a chip can only reverse the outcome if the difficulty equals the skill (net modifier of zero) or if the net modifier is positive (favoring the player). If there's any net negative (against the player) modifier at all, the chips become useless. Is that what you intended?

- Walt

[Eddy Fate]

Hi Eddy,

Are you saying that rolling the points have to be hardway rolls?

Yes, that was my original intention.

The odds are 1 in 36 for all such rolls. This wouldn't put many chips in play. (On average, only one in every six rolls of 7 could be reversed by using a chip.)

I debated at one point making it when ANYONE rolls your Point, but I was afraid that would put too MANY chips in play.

You could allow all the craps points, 4, 5, 6, 8, 9, 10, and allow them to be rolled any way, as in craps. The odds are different for different points, of course (1/12 for 4 and 10, 1/9 for 5 and 9, 5/36 for 6 and 8), so you could use shifting of the points as a mechanism. At 4 and 10, you get on average enough chips to make half your sevens into successes, and things get better from there. (If that's too generous, require two chips to reverse a 7 roll).

Hrm.  I didn't want to involve too much math, but maybe everyone can get a chip on a 4 or 10.  I'll have to consider that one - that way there's no extra Points to track.

If only hardway rolls count for Points, I see a problem with betting on other players' Point rolls. The odds are so steep that you'd have to offer a big payoff (at least 30 to 1, which is the sucker bet most casinos offer) to make it worthwhile, and that could really skew things if a bet pays off. Regular any-way point rolls with better odds would be easier to manage.

One idea I had was that any of the above would generate a chip - you're betting that the Shooter (rolling player) would EITHER roll a 7, their Point or your Point.  Would that shift the odds to a more level percentage?

As written, a chip can only reverse the outcome if the difficulty equals the skill (net modifier of zero) or if the net modifier is positive (favoring the player). If there's any net negative (against the player) modifier at all, the chips become useless. Is that what you intended?

Yes, to a degree.  I wanted to downplay luck.  However, considering the scarcity of chips, maybe making any "chipped" seven a success, regardless of the difficulty, would put the critical success/failure mechanic right in the middle of the probability curve.  But that might make hard successes/failures pretty frequent.

The idea was that the natural seven would cause players to make a choice - mainly "is this roll worth it"?

(Edit - And thanks for the feedback!  I really appreciate it!)