This week, I did make some more progress on theories and evidence; I now have specific content for what happens in the draft scenario, and half of it is written up. I can see that this mechanic will be good discipline for people writing for the game.
In Kannagara, theories will define the world. The default assumption will be that the personae come up with true theories, but there will be rules for having the personae get the wrong end of the stick. (If I can manage it, there will also be rules for leaving things open, but I think that might prove to be impossible to run.) When the personae are wrong, the players define the world negatively, and most likely also determine which theory is true. Most setting fluff will, therefore, be in the form of theories that the personae could form.
The mechanics for theories involve gathering evidence, and then creating the theory. The evidence consists of specific, concrete things that the personae observe, and they should generally gather quite a bit before they come up with a theory. This means that an important part of the write-up of any theory is the evidence that the personae have for it.
This is good discipline because it enforces “show, don’t tell”. In Kannagara, you cannot just write that somewhere looks haunted. You have to give the specific observable facts that make the personae think that it is haunted. Further, it means that, for any theory, you have to give some thought to how the personae could figure it out. There are rules for making the jump from evidence to theory, so you do not need to fill in every step, but you have to have at least an outline of the steps. This is something that is often overlooked in roleplaying writing; the author knows the secret, and so just considers what happens when the players discover it, rather than concentrating on how they discover it.
If course, in Kannagara the author does not decide which theory is true. The players do that, in play. It would be bad practice to assume that the players will always reach a consensus on what the truth should be, so the rules need to make a decision.
This comes in two stages. First, the players can choose which evidence they discover, and each player can choose to discover evidence favourable to her own theory, and problematic for the other theory. If the players do not agree about the best theory, this will lead to ambiguous and confusing evidence, which is a good thing; real life is like that sometimes, and if the evidence found in the game were always clear and unambiguous, it would impair suspension of disbelief.
The next stage is the creation of theories. Each theory needs enough evidence to support it; there is a minimum amount of support a theory must have. However, the persona creating the theory also needs to incorporate the evidence against the theory. Incorporating this evidence means that the theory contains elements to explain it away. This does not support the theory, but if the persona does not incorporate that evidence, it weakens her theory. The amount of evidence a persona can incorporate depends on her knowledge of the field, so a more skilled persona can deal with a lot of negative evidence while still creating a strong theory.
The truth, then, is the strongest theory of those that have the minimum level of support. The evidence has an influence on that, but a very good theoretician could overcome a lot of negative evidence, as long as she had at least some positive evidence for her position.
Sometimes, of course, theories are wrong. Getting the theory wrong will be a form of complication, but complications are shaping up to be an important part of the game that need their own post.