When playing ptolemies I build a libary which supposes to reduce building cost and time for 15%.
But when I built a wonder thereafter, It cost me 1000 metal as usual and my resource counter was lowered that numer. Should be 850, with 15% discount. Other buildings the same, and building a house with 1 worker is the same 30sec built counter starting with 29 sec left as without a libary.
It seems to me this is an error, because I do not notice an effect