Default Skill Theory - Page 2

Ezra · 02-14-2022, 06:50 PM

Why are default penalties set as they are, for example -5 to average difficulty skills?

Knowing how much thought went into GURPS, I suspect that a -5 default penalty to average skills was not arbitrary, but probably chosen with a rationale (and a mathematical one at that). Looking at the probabilities on B171, I see that someone with a 10 default attribute, or 50% probability of success, will roll against a 5 for an average default skill. Moreover, the probability of rolling a 5 or less is roughly 5% (1/10 the probability of the associated attribute). the ratio does not remain static, however. Since someone with an 11 skill (62.5%) would roll against a 6 (roughly 10%), although at 15-16 the ratio returns to roughly 50%, and at 17-18 swells to much better than 50% for a default skill.

As someone who likes to host and run games, I like to understand the rationale behind the rules in order to better explain them to the players.

02-14-2022, 06:50 PM	#1
Ezra Join Date: Dec 2018 Location: Hirakata, Osaka, Japan	Default Skill Theory Why are default penalties set as they are, for example -5 to average difficulty skills? Knowing how much thought went into GURPS, I suspect that a -5 default penalty to average skills was not arbitrary, but probably chosen with a rationale (and a mathematical one at that). Looking at the probabilities on B171, I see that someone with a 10 default attribute, or 50% probability of success, will roll against a 5 for an average default skill. Moreover, the probability of rolling a 5 or less is roughly 5% (1/10 the probability of the associated attribute). the ratio does not remain static, however. Since someone with an 11 skill (62.5%) would roll against a 6 (roughly 10%), although at 15-16 the ratio returns to roughly 50%, and at 17-18 swells to much better than 50% for a default skill. As someone who likes to host and run games, I like to understand the rationale behind the rules in order to better explain them to the players.