alt Hacker NewsThere are so many different variations of the rules, especially scoring. Scoring can vary even from family to family.
We've been learning for a few years now and still ignore things like prevailing winds and I don't remember what else off the top of my head. Basically we have a document of our own rules and we add to it as we get more advanced. Eventually we'll play with the winds and seasons and the goal is Hong Kong scoring.
just played with an American friend who was learning for the first time yesterday. The winds are by far the most annoying part. Not only is the order of them different than what most people are used to (ESWN vs NESW) but the points you get for each depend on what wind you are and this is on top of having to memorize the Chinese characters (although of course some sets number them). Great game but so many little special cases that can make it intimidating to learn.
Don't even get me started on scoring when you are gambling (although the dynamics of who pays who and how much is interesting)