Random Encounter Chart Generator, v. 1

There was a bit of talk on the Shadow of the Demon Lord G+ group about creating random encounter tables by group "tier" (starting, novice, expert, master) as a way of defining zones of safety for your players. As in: sure, you can go to the Nightmarish Hellscape of the Weird at level 0, but the first time the GM rolls on the encounter table you're gonna get eaten by an encounter aimed at master groups.

I was going to write up some generic encounter charts based on the Encounter Difficulty table on page 180 of Shadow of the Demon Lord. I wanted a reliable way to make sure the average encounter on any table I created would be exactly where I wanted it, so I started messing around with how the math would work out if I wanted, say, an average encounter Difficulty of 15, a minimum Difficulty of 3, and a maximum Difficulty of 30. (In other words, a chart that more or less covered the range of Difficulty appropriate for starting characters, assuming I don't want a Hard encounter in my random table.) And then I started to do it again for novice characters. And then I remembered I'm a software developer. So I wrote an ugly little program to automatically create encounter tables!

So the program generates 2d6 tables, meaning you get a weighted table that (in this case) tends towards the average Difficulty. Basically, you give it a minimum, maximum, and average difficulty. It uses the minimum difficulty as a roll of 2, the maximum as a roll of 12, and the average as a roll of 7. (These are the two least likely, and the most likely, rolls of 2d6.) It fills in the other values with Difficulties that approach the min and max as they get farther from the center, and then tweaks them so that the total weighted average of the entire table is exactly the average you entered originally. Finally it generates a table for you. The left-hand column is your roll on 2d6. The center column is the total Difficulty of that entire entry. The right-hand column is the average Difficulty one monster should be, assuming the encounter is made up of 1d6 monsters of the same Difficulty. (Which not all encounters will be, but it's a useful tool for simple encounter tables.)

Here it is!

The little program is in a JSBin, so you can easily see the source code. Like I said, it's ugly. I banged it out over a lunch break and didn't refactor at all, so don't judge me professionally from this! But you're welcome to copy the code, play around with it, and find my mistakes. (Just don't change it within the original Bin, so other people will find it as I originally wrote it.) And hopefully, make some random encounter tables!

Eventually I want to expand this. First up would probably be rounding to integers, and maybe rounding the average monster Difficulty to the numbers in the core rules. (There's no monster of Difficulty 4.09622...) Then maybe some suggested ways to break up the total Difficulty of the encounter. We'll see.