Rating Zendo Rules
I rate the difficulty of a Zendo rule on a scale from 1 to 9, where a level 1 rule is very easy and suitable for a new player, level 5 is tough and interesting for a moderately experienced player, and level 9 is a challenge for an expert. My rating is quite subjective, and based on many considerations.
First, I consider the rule and see if, as a player, I would state it differently, perhaps as a negative. Also, if I would likely make a very revealing “show me” guess, I mark it as easier, although probably lots of fun. For example, with the rule “exactly one-third of the pieces are blue“, I’d probably guess “it has three pieces, only one of which is blue,” and the master would make a six piece koan which would lead me to the correct answer. It can create a very satisfying game.
Second, I tend to make an initial rating based on how many factors the player must pay attention to. So if a player must notice both color and size, I start with two. I add one for a negative rule, one for cumulative effects like number of colors, one for pointing, one for touching, and so on. I also think about the koans that would be made in the game, and think about how salient the important stuff will be. “There is a red piece pointing at a red piece” is really easy because each white koan will have a red piece pointing at a red piece, and that is very salient.
Lastly, I think about the level of various players I have been master with, and think about what would be easy or hard for them. That just takes experience as both a master and player.
Another important note is about how the master controls the level of difficulty. As master, you can create initial koans and disproving koans that make a hard rule easier and an easy rule harder. For example, “If there are an equal number of red and blue pips” is really hard if your positive koan has neither red nor blue pieces, while “If the value of red pips minus blue pips is positive and odd” is much easier if you start with a single small upright red and a single small upright green. All rules are harder if you start with convoluted koans. And if you disprove my “show me” guess with a complicated koan, it will make it hard to glean any information from it. With this in mind, the way you run the rule, and the way that the players play it, can change the level up or down by about two ratings.
Here are a bunch of rules that I have rated in the past. I have reviewed them, but there may be inconsistencies which I’d love to hear about so I can fix them.