Exploding Dice

[Samael]

Hi All,

I've seen the topic of exploding dice or open-ended rolling come up a few times and wanted to add my two cents.  My last experience with the concept was when rolling d10s, where a result of 10 garnered a new roll whose result was added to the previous.  The problem I had with this system was that a 10 could not actually be rolled.  Here is my solution, called The Exploding d10.  Note that I only throw one die at a time (mainly because I think using this in a bucket of dice system would be a hassle).

First, you need a d12.  Yes, a 12-sided die, not a d10.  Rolls of 1-10 are read as normal.  Rolls of 11 Implode (explode downwards); rolls of 12 Explode (upwards).  In both instances, a running tally is kept.

Implosion (initial roll of 11):  The base result is counted as a 1 and the die is thrown again, with the result being subtracted from the previous result.  If this new roll is also an 11, 10 is subtracted and the attempt implodes further (an additional die throw).  If a 12 is thrown during an implosion, the running tally is not modified any further and the die throwing is finished.

Explosion (initial roll of 12):  The base result is counted as a 10 and the die is thrown again, with the result being added to the previous result.  If this new roll is also a 12, 10 is added and the attempt explodes further (an additional die throw).  If an 11 is thrown during an explosion, the running tally is not modified any further and the die throwing is finished.

And a few examples.  Bob throws an 11.  This is counted as a 1 and he rolls again.  This time he gets an 11 again.  1 - 10 = -9, his current total, and he has to roll again.  This time he gets a 3.  -9 - 3 = -12.  He's done rolling.

He throws an 11 (counted as a 1).  His second roll is a 12.  His final result is a 1.

He throws a 12 (counted as a 10).  His second roll is a 12, for a running total of 20 (10 + 10 = 20).  His third roll is an 11.  He's done rollling, with a final result of 20.

He throws a 12 (counted as a 10).  His second roll is a 7, for a final result of 17.

Make sense?

Anyway, this is the system I'm using in a game I'm developing and thought that others might be interested in the mechanic.  Sorry for the lengthy post.

[joepub]

I've seen the topic of exploding dice or open-ended rolling come up a few times and wanted to add my two cents.  My last experience with the concept was when rolling d10s, where a result of 10 garnered a new roll whose result was added to the previous.  The problem I had with this system was that a 10 could not actually be rolled.

Hm? Why could a 10 not be rolled? Were you counting the "0" face as a zero or a ten? Most people/games count it as a 10.

The implode thing is cool, but slightly complicated.
What happens with negative die results? Do they cause some kind of epic, horrible failure?

And... if 3 players all do this, it's conceivable that they end up with scores like: -13, 3, 18. The gaps that can be created with this kind of thing are extremely large. Is this intentional?

[Callan S.]

Well he's right in that if you roll a ten then roll another dice and add it, you can only get an 11 or higher.


Hi Samael,

Is not being able to roll a ten getting in the way of what your game does?

Also - you could simply treat the exploding dice as value 0 - 9. If you roll a 0 on it (normally a ten), that means you get add zero to your original ten, still leaving you with a result of ten.

[Thenomain]

Also - you could simply treat the exploding dice as value 0 - 9. If you roll a 0 on it (normally a ten), that means you get add zero to your original ten, still leaving you with a result of ten.

Then you're casting the same die in two different roles.  (Pun partially intended.)  If the first roll is from 1-10 and the potential second is from 0-9, and this may be confusing.  Also, this subsequent die can't further explode, unless you say you reroll 9s on the second die, further muddying the waters.  Now, making all rolls 0-9 with the d10 makes a bit more sense, but I don't know how unpopular the twist in convention would be.

The imploding d10 (Samael's idea) could work well when you're adding to or subtracting from a base number, a la Fudge/Fate.  Games seem to be using smaller steps, so I don't know where lies the need for a scale of about -9 to 20 (1 - 10 to 10 + 10).  But if you needed an exploding/imploding d10, yeah, this seems to work pretty well.

[Leviathan]

Hm? Why could a 10 not be rolled? Were you counting the "0" face as a zero or a ten? Most people/games count it as a 10.

As Samael stated, it is the number itself that can't happen. You can roll 1 through 9, but then it suddenly jumps to 11 and onward up. In theory each time you roll a 0, you instead get 1+1D10 added on.

Is not being able to roll a ten getting in the way of what your game does?

I think Imploding/Exploding D12 is interesting, but I have to agree with this question. Does it help the game, or does it simply complicate the game. In most games I have seen, the jump of 2 points instead of 1 is really not going to affect the functionality of the game. I think that if you are looking to use this sort of dynamic, it should be because it enhances the gameplay rather than simply out of a dislike for the disappearing 10's. Just my thoughts. As I said, it is interesting if nothing else

[TroyLovesRPG]

Its a dicey situation, no pun in 10 did.

The thing about the exploding dice for 1d10 is that 10 is always the target number. If you roll 10 then you add the value of another die roll. It wasn't implied, but as long as you keep rolling 10, you continue to add 10 then roll another die.

Instead, use the initial die roll as the point die. Roll 1d10 and note the number. Roll another 1d10. If the second roll is the same as the first then add 10 to the first roll. If it isn't the same number then you use the first die roll and stop. You can stop there if you want to only allow one "explosion"; otherwise, roll another die. If the die roll matches the point die then add 10 and roll again. If the latest roll doesn't match point then just add the value of the die roll and stop.

Step by step:

1. Roll 1d10. This is your point die, so leave it on the table.
2. Roll another 1d10.
  a. If it matches the point die then add 10 to the total. Goto Step 3.
  b. If it doesn't match the point die then use the original die-roll. Stop.
3. Roll another 1d10.
  a. If it matches the point die then add 10 to the total. Goto Step 3.
  b. If it doesn't match the point die then add the value to your total. Stop.

This works because any number on the die is the potential "explosion" number, not just 10. In fact, you can use this method with any die type and it will preserve the highest number that you could roll on that die.

Troy

[Samael]

Yes, I should've mentioned that I read a result of "0" to mean "10"

Troy, I like your idea, but how do you implode?  I like symmetry.

I disagree with the notion that there's no difference between 1 pt and 2 pts.  There obviously is; it's the difference between success and failure.  Now, if one were to work up a set of charts that had to be referenced to define the levels of success, then yes, it could be done to incorporate that.

I have to admit that I'm snickering a little at the notion that this is complex.  When I design games, there is generally one mechanic.  I can point to any number of other games (developed here) that are confusing in their mechanics (Sorcerer immediately springs to mind.  Very cool game, I just have issues with its task resolution).  Too each his own, I guess.

[Thenomain]

I have to admit that I'm snickering a little at the notion that this is complex.

I for one said it may be complex, and only in reaction to Callan's "the second die could be 0-9 instead of 1-10". Samael's system -- which expands on this -- easily doubles this complexity as the roll depends entirely on which iteration of an explosion you're on.  It's very cumbersome.  First Roll: die value.  Second Roll: 0 or 10-and-again.  Third and Consecutive Rolls: die value minus one or 10-and-again.

I think you're better off making each roll for a single system aspect react the same as each other roll, regardless of where it is in the iterative chain.  Already you have a rule that states, "When you get an implosion result (11) on an explosion chain, or an explosion result (12) on an implosion chain, treat it as a 0 and stop."  It's seems to me to be much easier to follow a rule like this than change what the die means depending on what you've rolled before.  At least with yours, the exception is only for the non-numeric results.

I've been thinking how doing this with a d6 (d4 explode/implode) would work for Fate, but as you're usually going to score positive I'm thinking "not very well".

If that's not a concern for the game design, just say so; it's all cool.

[Callan S.]

Then you're casting the same die in two different roles.  (Pun partially intended.)  If the first roll is from 1-10 and the potential second is from 0-9, and this may be confusing.  Also, this subsequent die can't further explode, unless you say you reroll 9s on the second die, further muddying the waters.  Now, making all rolls 0-9 with the d10 makes a bit more sense, but I don't know how unpopular the twist in convention would be.

Oh, phoey!

It's not confusing, its simpler than Samael's design. What it is, is non semetrical. If your looking to see a system which has a recurring pattern in its design, this isn't going to be confusing, its going to be jarring. It'd be like looking at a table where one of the legs is just an inch shorter than the others.


Samael : Have you ever had fun trying to work out a symetrical system with other people? I'm thinking of how universalis lets players work out new system parts together.

[Thenomain]

Oh, phoey!

It's not confusing, its simpler than Samael's design. What it is, is non semetrical. If your looking to see a system which has a recurring pattern in its design, this isn't going to be confusing, its going to be jarring.

Tomayto, tomahto.    Point taken, though.

And excellent use of the term "phooey", sirrah.

[Conteur]

Great idea but I think it depend on the rule system. In my game, all the dice are made this way soon a D10 if you score a 10, you explode. If you score a 1, you implode. Then, if you were exploding and roll a 1, you stop there. If you are imploding and roll a 1, you also stay there. The things get ugly if you implode and roll a 10 because you explode downward.
So, you could roll -26 on you're dices! My botch are related to the distance you are from the target number(generally 20), so you are very unlucky.