D6 System: How would you make this kind of dice-roll?

I want to make a macro to roll dice as per the D6 System (West End Games, for original Star Wars, Ghostbusters, Men in Black). In this game, only d6's (D's) were used. Skills were given different strengths which followed a sequence of "fractional" dice-values or "pips" as follows: 1, 2, 1D, 1D+1, 1D+2, 2D, 2D+1, 2D+2, 3D, 3D+1, etc. When rolling any dice-roll, one die had a different color or designation, and was the Wild Die. If the Wild Die comes up a 1, then you remove the Wild Die and the highest dice value rolled in the remaining dice. (This rule is not used if you are rolling bonus dice from spending Character Points. Character points can add dice after the initial roll, and you can spend up to but no more than 2 to get 2 extra dice.) For example, a character attempts a pistol shot with a Marksmanship Skill of 4D+2. The player rolls 1 on the Wild Die, and 5, 4 and 3 on the other dice. The player removes the Wild Die and the 5 (making the total from the dice 4+3), adds the modifier of +2, for a total of only 9. (The rule of 1 on a Wild Die is not used if you are rolling bonus dice from spending Character Points.) If the Wild Die comes up a 6, you may add 6 to your total and roll the Wild Die again, adding that new die to the total as well. If the Wild Die comes up a 6 again, you may again add that 6 and roll again. You can continue rolling the Wild Die for as long as you get a 6 (a "cascading" or "exploding" die), but must stop after any result other than 6. Rolling a 1 on the Wild Die after a 6 is obtained does not incur any further penalty (no dice are lost). (The rule of 6 on a Wild Die IS applied if you are rolling bonus dice from spending 1 or more Character Points; in other words, one die from Character-Point dice is always Wild.) For example, a character attempts climbing a nearly vertical cliff with a Climbing Skill of 5D to make a Difficult roll of 20. The player rolls a 6 on the Wild Die, and 3, 3, 1, 5 on the other dice. The player can total all the dice so far (18). He gets to roll the Wild Die again, and again gets a 6. The total so far is 24 and he may roll again. He rolls a 1, and stops. His total is 25. He does not lose dice if the Wild Die came up as 1 after having successfully rolled one or more 6's. I would need a Macro for a regular dice roll (Wild Die of 1 causes a penalty but is Exploding if it is a 6), and for 1D or 2D rolled as a result of spending Character Points (no penalty for a Wild Die of 1 but a 6 may Explode).

I may have written a script for this already: <a href="https://app.roll20.net/forum/post/1653655/#post-16" rel="nofollow">https://app.roll20.net/forum/post/1653655/#post-16</a>... If necessary, I can tweak it a bit for you. =D

I'd look at the d6 Star Wars sheet, first, to see how they do it. The compare-and-removal of the dice sounds like an API only thing. I made a Mass Effect (d6) sheet, and it this way: (@{Attribute_dice} -1)d6 plus 1d6! plus @{Attribute_static}...plus however you want to do skills. This would roll a number of d6's equal to the Attribute_dice, with one of them exploding on a 6, and add the static bonus associated with the attribute, plus however you work skills. Anyone would have to mouse over the dice results if a 1 was rolled, and doing some simple math. There is a method on the wiki for sorting the dice results in descending or ascending order, so that would make finding the highest die faster. Character dice, which sounds like more Wild DIce that only do good things, could be done as a modifier per roll. Just add: + ?{Character Dice|0}d6! ...to the buttons. It will ask for how many character dice to add. If I was going to do a roll template (and I highly suggest doing a roll template, I would again roll the attribute -1, and have the wild die listed separately, in a separate color. I had lots of fun with the old d6 Star Wars, so if you want some help, I will gladly lend a hand.

The Aaron, that's good stuff. In my version of the D6 rules, though, the Wild Die roll of 1 means remove both the Wild Die and the highest roll, so my rolls (in the Men in Black game) are 1 less than shown for a critical fail. Once a die is rolled, a player may choose to spend 1 or 2 Character points to add to the roll. The roll includes a Wild Die, but no penalty for a 1 roll. If 1 point, roll 1d6!. If 2 points, 1d6!+1d6 (a Wild Die that may explode, and a regular die).

Subtracting the Wild Die on a 1 is an easy change. The other is slightly harder. Your players would roll the dice with the command, then choose based on the results to add any of: Nothing 1d6! with no bad result on a 1 1d6! + 1d6 with no bad result on a 1 That sound right? I'd probably implement that with a couple API buttons on the end of the display that would represent the roll with the addition of the 1d6! or 1d6!+1d6.

That is correct. I could just handle Character Point dice additions as a separate die roll (no penalties on a Wild Die of 1), but it would be particularly cool to offer it as an add-on operation, default of 0 added dice. The players choose to spend Character Points after the roll; they don't have to agree to it beforehand. There is something else called a Fate Point; players generally never have more than 1 at a time to spend. This allows them to DOUBLE the dice rolled, but they must commit to doing so before the roll. Because the pips are considered rough "one-third of dice" in probability, doubling 3D+2 works out to 7D+1 for example. That is so tricky to figure out as a macro that we would probably just have to figure it out in our heads.

If you can give me some examples showing all the steps, I can provide that in the API.

Okay, I didn't reply for a few days but here are game examples. According to the MEN IN BLACK RPG rules, let's say I have a character with a Marksmanship Skill of 4D+1 (D=d6), 5 Character Points (there can be a maximum of 10) and 1 Fate Point (characters start with 1 but can gain another if they fulfill a Cue Card). A player can spend 1 or 2 Character Points AFTER the dice-roll to roll an extra D or 2D. One die is always a Wild Die so it's either d6! or d6+d6! to add to the original roll. (a roll of a 1 on the Wild Die inside a Character Point add-on roll will cause no penalty; it's just a 1. A roll of 6 on this Wild Die can explode as usual.) Fate Points allow the roll to be doubled but I must choose to do so BEFORE the roll. The Wild Die acts as usual (6 exploding, 1 taking itself and the highest die away). So before the roll, it should ask me what my die-roll is and to add or subtract modifiers. The math is a little tricky with adding dice and fractions of dice called "pips" (always indicated as +0, +1 or +2). So (3D + 2) + (1D +2) = 5D +1. Let's say I get a +1 bonus from range and decide to spend a Fate Point to make my shot as good as it can be. Doubling 4D + 2 gives me a whopping 9D +1 = (4D x 2) + (2 x 2) = (8D) + (4) = (8D) + (1D + 1) = 9D + 1. Say I roll a Marksmanship, unmodified, and get 2, 5, 6 and 4 on the Wild Die. A straight total, that makes (2 + 5 + 6 + [4]) + 1 = 18. However, if I roll 2, 5, 1 and a 6 on the Wild Die, I keep the 6 and roll the Wild Die again. I then get ANOTHER 6, so I can add that too, roll it again and get a 1. A 1 from after the first roll of the Wild Die does not bring a penalty, so my total is (2 + 5 + 1 + [6 + 6 + 1]) +1 = 22. Let's say I roll a nice 3, 5, 6 but the Wild Die is a 1. I must take away the Wild Die AND the highest of the other dice rolled, leaving me with (3 + 5 + [0]) + 1 = 9 only. I really need to make a Difficulty Level of 15 (the usual default or average), so I am asked if I want to spend 1 or 2 Character points. I choose 2 and get a roll of 5 and a Wild Die of 6. Roll Wild Die again and get a 3, so the total is (3 + 5 + [0]) + (5 + [6 +3]) + 1 = 23. An ideal, all-inclusive Macro would ask me for modifiers, then ask if I wanted to spend a Fate Point and arithmetically double the roll, and make the roll with attention to what happens with a Wild Die of 6 (explodes) or 1 (removes itself plus the highest of the other dice). Then it shows the result and asks me if I want to spend 1 or 2 Character points (d6! or d6+d6!). A roll is made, but for Character points a Wild Die of 1 does not penalize me, it's just a 1 and I stop rolling same as for 2-5. That would be my dream macro. Fate Points and Character Points would be subtracted from the Character Sheet and/or Token automatically if spent. I ask for a general rolling Macro, not buttons linked to each Skill because there are too many Skills and you can create Skill specializations as well, and that would clutter the Token pop-up Radial Menu.