You can see it quite well if you look at the coeff 6s: the french forum has a thread where the highest numbers of coeff 6s of one kind are listed. For example someone got 7 golden mushrooms so far, another player got 5 purple pearls, and so on. The effect item numbers are somewhere around 5-7 each while the point item numbers are always around 2 or 3. This is a quite big difference, and there are four effect items and four point items, so I would say the first way (see above) is right.Interesting ... You certainly have a point. This gap indeed seems to suggest that the game selects an item individually, based on the whole set, rather than first selecting a coefficient set. So (I think) this implies a dynamic system, as I theorized in Neko's thread: it means that the chances are relative to the number of items you can get. This would also support kensainasir's explanation for already having unblocked both Books:
All my coeff 5 I reached in first 3 month cos If you not finish some quest you can't find many "easy" items and there is much biggest chance to find rare items. It's not fair but it's true.I say "implies," not "necessitates," because of course it could still just be a coincidence. Or it could be based on other external factors, such as the point items' families taking longer to unlock (although I don't think this is true), or something else we haven't yet thought of.
