[Chazar]

Lowly unique items and summons sounds interesing...

...could imagine research races for unique +1 path boosters...

...but then again, there might be a balance problem if some nations get access to things that were not meant for them, and it might get boring if an opponent bases its strategy on winning the race...

...however, if there would be a single unique pair of Earth Boots in Construction 4, this would be a nice reward for a good researcher, but would not breakk anything...