As the title says, just a number (comparable to duration on a temporary buff) in, say, the top left corner of a buff showing how many are up vs how many you can have, i.e. (1/3) or (2/2).
I'd have to agree. You would NEVER know that certain buffs stacked (Mushrooms anyone) unless you found out from the forums, looking at your stats and experimenting, or dredmorpedia.
While we're talking about buff icons, how about changing the font for number of turns remaining so it's visible even if the buff image is close to the same color as the font. Is it possible to add a black outline to the font, or simply putting a black rectangle behind it? Or, perhaps put the remaining turns counter and this new buff stack counter underneath (or above) the mana upkeep counter, and not on top of the icon at all.
A UI fix for showing stacked buffs has been in the hopper for some time (see: ui/buffstack.png for the stacked card effect). It'll happen sometime within the next patch or two.
On a similar note, I cannot see how many number of hits for a brittle buff when any other buffs are on the right side of them. Fixing this issue would be a great opportunity to take Glazed's idea above and fix it the same way. I think they need a bit more space to work reliably. As it is I never really know if I am about to run out of hits or if I can wait a bit longer before rebuffing. If anyone else does not know what I am saying, I can screenshot it to demonstrate. *Edit* I am not sure if your fix for this would even touch this particular issue dbaumgart.
