Mining Knowledge in GURPS : Part 1. Character knowledge

This post is the first part of three on character knowledge, mining for, and designing sources of knowledge. The emphasis of this post is on character knowledge: the skill-based abstracted knowledge that players can invoke to fill in details in an adventure. As a GM, I used these as potential monkey wrench as I leave it up to dice to determine how much PCs really know before they walk into something. 

Topic Plan

• Part 1 : Character Knowledge
• Part 2 : Designing sources of information and Research
• Part 3 : Learning and skill advancement 

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Area Knowledge, Lore and History

These skills is a key in my campaigns. I don't really think that I'm handling it very differently than anyone else.  As a GM, I like to use dice to determine character knowledge because it sends the story into unpredictable paths. Knowledge-based skills are weird because, by being anchored on IQ, seem to make the strange assumption that smarter people would know more than other on a topic after being exposed to it for the same amount of learning or experience. In the defense of the RAW, we can always argue that the smarter people will get more insight from the same quantity of information, or that it takes less character points to be able to recall the same amount of useful details.

Case 1 : What is the answer to question X?

A PC has Area Knowledge(Shire)-10: what does it means? It means that this PC has  50% to know a fact about the Shire. Or more precisely, that if we'd poll 1000 "locals", only 500 would get the answer right. A common knowledge about the shire would mean that, say 90% of the folks know about it (90% is about a target number = 14 on 3d6, or thus +4). The PC would have thus skill+4, or 14 as its effective level of knowing this fact. Interestingly, someone with Area Knowledge(Shire)-13 would have a net target of 17 (99.5%). A little learning, or a good IQ goes a long way when playing this game. Here are some examples of trivia knowledge and related modifiers that I came up with:

Modifier	Prob (%)	Examples
-7	0.46	What is the name of the fiancee of Old Farmer took’s third son?
-6	1.8	How many sons does Old Took has?
-5	4.6	Where is Old Took’s farm?
-4	9.3	Is Old Took’s farm beside the Mill?
-3	16
-2	26	What is the shortest path to the Mill from here?
-1	38
0	50	Where is the Eastfarthing Mill?
+1	63
+2	74	Where is the nearest Inn from here?
+3	84	Where is bag-End?
+4	91	Which village is just north of Hobbiton?
+5	95	Where is Hobbitton?
+6	98	Is Eastfarthing East of WestFarthing?

In case of a mismatch between the skill used and the question. I use the GURPS task difficulty (Basic p.345) to stack an additional penalty to the check. For example, knowing about the Shire is very unfavourable in answering a general question about Bree (-2), but could hardly be used to answer a general question about the Misty Mountains (-4). -2 means that about 1/4 of the Shire folks would know, while -4 implies that only 1 in 10 would know this details about the Misty Mountains. If the query was more specific than "general", apply a second modifier as described in the previous section.

In mid-play, there is no need to sweat the details: get an intuition for the meaning of these penalty and pick one that is about right! Case 1 is a binary case: you either know something or you don't. The next sections uses the margin of success to selectively release information.

Case 2 : What do I know about topic X?

This is such a common question. This case is a good way to reward players researching and using their knowledge to prepare an adventure. I used it in the Palantir campaign often, and in critical places. Instead of carefully preparing a laundry list of everything that a PC knows about something, I get them to roll and reveal knowledge as needed (and narratively convenient) based on the check's margin of success.

For information that I want to provide beforehand (push information), my prep-work comes down to a list of facts that are ordered from general to specific. For example, a Finbert enters Minas Tirith to report to the citadel. The question is "What do I know about making my way to the Citadel?". The city is imposing, almost oppressive. What does Finbert knows about it before entering?

Margin of Success	Known by (%)	What does he knows
-6	98	Mmm, Minas Tirith is a large city with levels
-5	95
-4	91	There is seven levels in Minas Tirith. The 7th level is where the citadel is.
-3	84
-2	74	There is a road going up to the Seventh level.
-1	63
0	50	The main road winds all the way through each gates.
+1	38	It takes passwords to go through the 7th Gate.
+2	26	There is a good Inn on the 5th level with Hobbit rooms.
+3	16	It is possible to find good pipe-weed on the 4th level, from a man called Heron.
+6	1.8	The captain of the 7th Gate is called Marion, he is a history buff and a pipe-weed afficionado (euphemism).
+8	--	There is a secret passage on the 6th levels that is used to sneak into the 7th level.

Making queries about other topics in Minas Tirith should be independed rolls, unless the topics are closely linked. If so, the next roll may be granted +/- 1 (or 2). But try to keep the checks separated: it isn't because Finbert knows about Marion, Captain of the 7th Gate's drug addiction that he should know any particular details about the city's storm drain system.

Re-rolling on knowledge

As a rule of thumb, don't. A knowledge check should be about what they know, or can recall from a close-at-hand source without doing research. If you feel like re-rolling, then you might as well decide what piece of information you want to pass to he PCs and spare them the dice rolls. There is nothing wrong with it, I just don't think that it is as much fun. Fun overrides everything. 

Part 2 will be about research and discovery. It will also cover the acquisition of skill points into knowledge skills. If the knowledge check falls short, this is the next logical step to take.