Stone Idol

[GrudgeBringer]

We where in a discussion about The merits of the Stone Idol and a couple of other questions came up that I never had really thought of.

I need just a simple answer (lol, if there ever IS just a simple answer in this game).

If you have more than 1 Stone Idol in a province, do the effects stack?

And the questions that arose out of that is...(and I will use skeptics as an example) How many skeptics can you put in a province before you get diminishing returns, or they are just better used elsewhere. (although I am using skeptics as an example, I am referring to all dominion reducing mages etc).

Thanks