Mon Oct 24 16:05:49 2011 by Torben |

I'm working on a homebrew RPG called "Dark Coast". You can find it at `http://www.diku.dk/hjemmesider/ansatte/torbenm/DarkCoast/` .Dark Coast uses a rather unusual dice-pool system. As usual, ability (talent level) is measure as a number of dice, but unlike other systems, so is difficulty (challenge level). The system is fairly simple: At talent level T and challenge level C, you roll T+1+C d6s, drop the T lowest and take the now lowest as the result. Equivalently, you can drop the C highest and take the now highest as the result -- you get the same number either way. The resulting number (between 1 and 6) is interpreted as a degree of success, with 1-3 being various degrees of failure and 4-6 being degrees of success. With fixed C, the success chance increases with higher T and is exactly 50% if T=C. But apart from the symmetric case, analysing probabilities by hand is not easy: Though you can find a closed formula for the probability of Nth-lowest of M dice being at least K, this is rather complex, so it is easier to use Troll. In Troll, you can simply write `min largest (C+1) (T+1+C)d6` where T is the talent level and C is the challenge level. There is no operator in Troll for dropping the T lowest dice, so I instead keep the C+1 largest, which is the same when the total is T+1+C. Equivalently, you can write `max least (T+1) (T+1+C)d6` which drops the C largest dice and takes the largest of the remaining. If T>C, the first option is faster and if T<C, the second is faster: `least` and `largest` use time that increases quickly with the size of their first arguments, so you want to keep this small.I have added the above as one of the predefined examples on the Troll page, so you can try it out. |

Mon Dec 15 21:24:44 2014 by Daniel |

Hi Torben, May you post some rolls examples of Dark Coast Mechanic? I don't understand whell...there are 2 dice pools in a single roll? One for Talent other for Chalange? |

Tue Dec 16 11:44:22 2014 by Torben |

There is only one pool, but the number of dice is determined both by the Talent T and the Challenge rating C. Let us say that a character with Talent 3 is attempting a task with Challenge rating 2. We now roll T+1+C = 3+1+2 = 6 dice. Let us say that the result of this roll is 1 3 3 5 5 6. You now remove the T (i.e, 3) lowest and C (i.e, 2) highest results, leaving a result of 5. Results of 1-3 are failures and 4-6 are successes, so this is a success. With bonus effect even, as 4 is a normal success, 5 is a good success and 6 is an exceptional success. Similarly, 3 is a normal failure, 2 is a bad failure and 1 is a horrible failure. Another example: A character with Talent 1 is up against an opponent with Talent 3. The Talent of the opponent is used as Challenge rating, so we roll T+1+C = 1+1+3 = 5 dice. The result is 1 2 3 6 6. You remove the 1 lowest and 3 highest results, leaving a 2. So this is a bad failure. A third example: A character with Talent 0 is attempting a task with Challenge level 0. So we roll 0+1+0 = 1 die. The result is a 4, so the character achieves a normal success. |