I recently got into the CBP, I am an experienced Civ player with about 850 hours played. I started playing CBP on Immortal, but I'm having difficulties keeping up in Techs. I play a non aggressive style, focusing on protecting my borders rather than conquering the AI. I try to focus on science buildings as early as possible, and try to work as many science specialists as possible. I plant all scientists until roughly the industrial era. I have used both Tradition and Process policy trees, depending on which Civ I choose. I don't span settlers so my tech cost doesn't increase rapidly. I adopt rationalism as my Renaissance policy tree. I still find myself in last place in techs by the mid Industrial era. Usually 14 techs behind the leader. I usually end up stopping my campaign by then because it feels like I'm falling further behind in techs, not catching up. What are some tips to compete in Techs on Immortal/Diety ?, should these difficulty levels only really be used for conquering the AI?