grufflehead
First Post
Wow, I really like this idea.
BUT, I think that it would make sense to decouple monster knowledge checks from CR if this is going to work well. I really think that campaign settings should assign all monsters a rarity (common, uncommon, rare, very rare, unique) and these rarity ratings should determine the DC of the knowledge check. Perhaps the formula could remain the same, save that instead of CR, you used common=0, uncommon=5, rare=10, very rare=15, and unique=20.
Ken
A very good thought. Why oh why did they get rid of the 'Frequency' entry that used to be in monster stat blocks in previous editions of D&D? That would have been your answer right there.
Short of assigning them on the fly, I suppose, if you think figuratively, the 'Challenge' in 'CR' could include the relative difficulty in exploiting their weaknesses, which I presume was the original intent as it was written in Arcanis (one of the classes had an ability which was much like a 'floating' favoured enemy which could be triggered by studying an opponent and making the relevant Knowledge check which was where I got the idea from). Tougher i.e. higher CR creatures are almost by definition rarer in a lot of cases, so as an all encompassing mechanic it might still have some merit.