basic:
3 fully upgraded legs artifacts (15%*3)
Mansa Musa (30%)
polymath (10%)
space needle (10%)
library (5%)
100% in total
additional:
Hermitage museum provided another legendary artifact (15%)
parliament law bonus (10%)
You are completely correct.
It used to show 100% shortening as working, in which case the game would crash if you tried to research it.
Also, a time reduction of 86~99% was effective.
BHG said they would fix this bug and after months of waiting they have implemented an incredible "fix" that limits it to 85%.
BHG is taking advantage of a bug fix to make a downward correction.
Even if we accept the 85% limit, don't you think BHG should compensate for every third LAF and beyond?
Amazingly they want me to keep using the no longer trashed soul catcher that I traded for 300 tokens.
