Log in

No account? Create an account
11 March 2015 @ 11:43 am
Return to D20 fantasy heartbreaking  
Now that the Dragon-Blooded Charms are mostly done and Warlords of the Mushroom Kingdom is statting up monsters, I've returned back to my old Dungeons & Design series about making a fantasy heartbreaker, since it turns out that while I do like Novus a lot, it still does just enough things differently that I'm willing to spend hours kitbashing up something new based mostly on True 20 with added bits from Novus and Ken Hood's Grim 'n Gritty combat rules (PDF warning).

So, I read back over my old post about dice mechanics about bounded accuracy and dice curves, and I have a better idea than 2d10, which does have a bell curve but doesn't allow the full range of d20 results. However, rolling 3d20 and taking the middle keeps the d20 and the full range of results while making it a lot less swingy. Higher numbers are slightly more common than 2d10 and slightly less common than d8+d12, but the added benefit is that I can use the other dice to do additional functions. One concept I really like in Novus is how 1s and 10s always explode, leading to a larger randomization range even though it's not likely to happen, and while it's not quite as elegant with middle of 3d20 I did think of a reasonable facsimile. If any of the dice rolls a 20, add an exploding d6. If any of the dice rolls a 1, subtract an imploding d6. If there's both a 1 and a 20 on the same roll, add an exploding d6 gain a Conviction Point.

I tried to write an AnyDice program to demonstrate this myself, but there's enough complexity there that I couldn't get it to work right, and I don't understand Troll's syntax well enough to even make the attempt. I did go post about it on RPG.net, though, and the creator of Troll kindly wrote out a program that was a lot shorter than I expected:
x := 3d20;
m := median x;
if 20=x then \ if there is a 20
  m + sum accumulate i := d6 while i = 6
else if 1=x then \ if there is a 1
  m - sum accumulate i := d6 while i = 6
else m
Which you can copy over to Troll or scroll down the user rolls drop-down until you get to "Median 3d20 + exploding/imploding d6."

What I learned is that the odds of rolling a twenty under this system are 5.6%, which is almost the same as the base d20 system's 5% odds, and the odds of rolling a 1 are 4.3%, so it's very slightly biased above the usual d20 average due to the times both a 1 and 20 are rolled exploding and not imploding. But that's fine with me, and it means that I probably don't need to mess with d20 DCs at all, which is good! Less work for me!
Current Mood: thankfulthankful
Current Music: The H. P. Lovecraft Literary Podcast