Dice pool

The next basic mechanic that I have seen used is the dice pool. The main difference between the dice pool and static dice is a variable amount of dice or cards being used. This produces some different probability and depending on how the pool is "read" allows for the possibility of someone with a lower amount of dice to win.

How the dice pool functions is up to the system in place. The most common is looking for dice that have rolled above a number and count them as a success this is the kind that allows the lower dice pool to win because it is possible for the higher one to not even roll a success. A variation is to look for matches in the pool or other such combination of dice such as a number of dice showing a sequential pattern (1,2,3 or 2,3,4 for example) this type also allows for the lower dice pool to have a chance to win. The last one I have seen just adds up all the dice this method after a point falls into a problem of the higher dice pool being unable to lose by virtue of it always at least rolling a 1 for each die and the lower dice pool unable to roll higher then it's max value multiplied by how many dice is being rolled.

The main problem with this is while I do say there is a possibility of the lower pool wining this doesn't mean its common, it could even be lower then 1% and relies on the higher pool failing to roll whatever is counted up. This is desirable in a lot of cases but not when a few dice is meant to show little difference between levels of expertise. The one that shows this flaw the best is when the dice are just added up. I once suggested the use of such a pool as a simple system until we did some play testing and looked through the logs to find out that if the opposing roll had a larger dice pool they flat out won. I did some numbers and found what was an obvious flaw, the average of the larger pool was max range of the lower pool or close too it in most cases. Actual numbers placed a lower pool wining less then 20% at best when facing a pool just one die larger. Needless to say we have to rethink that problem.

In the end we also have to do a lot of work to know if we can do something, the only thing we do know is if we have more dice we just have a better chance. For most people this is fine, I would like to know and some Game masters would like to know beyond "this is a hard challenge" from the book. You can do a lot of crunching and generate as many tables as you could possibly expect to be rolled but another problem is hit. If your system is more complex then just counting success or combines methods you end up with something that is hard to calculate. In the Cthulutech system Framework I wanted to figure out how it worked but it combined matching and addition in an odd way. If you roll a straight you added it up same with matches. I was not able to figure out a formula or method other then going through every single possible roll, which I did through use of making a program. Oddly enough I found the average difficulty to be above what is probable but for a horror game it fits the them.

Now while there are flaws to the dice pool there are some advantages. One is a very natrual system of having a good bellecurve that differes between individual character abilities. Also as shown with ORE you can gain more then one value from these pools. With ore you look for matches and then have effects based off of how many you have in a particular match and what the match was. This produces some interesting things when utilized correctly, ORE even attempts to extract a third value based on how many are matched and what you are doing. There are possibly more things that could be done, such as using an ability to reroll a specific die in the pool which could be interesting though making figuring out what such an ability does harder to figure out.

Dicepools in the end have the most interesting possiblities for mechanics purely within the system but figuring out how such adition ultimatly effect how the pool works would be very hard. This makes planing encounters that much harder for game masters but ultimatly gives some intersting results in play.