Hi everyone i starting to learn piece by piece and starting to like it! but tho i'm having troubles when i recruit Heroes but i cant recruit more than 3 heroes how can i add more space to recruit more? It always seems the AI knows how but i couldn't.

Please look into Raptor's FAQ, which answers these and many other frequently asked questions. Please zoom into the techs in the west tech tree and look for the alien face like ET. He is on several techs which increase your academy cap.