The 'science victory' tech, Book of Mastery, actually isn't at the end of the tech tree like in most strategy games - in fact, it's almost a mid-game tech. For me that typically means I'll only ever recruit dragons, wield the most powerful magical weapons and armor or even conduct the epic level quests if I decide to refrain from or postpone casting Spell of Making. There's the option of turning off this victory condition, of course, but that's a pretty poor excuse for avoiding the problem. The question is, should Book of Mastery be moved back a bit in the tech tree? Should the Forge of the Overlord and the other towers cost more to construct (FotO costs 50 gildar to build, for instance, which is a laughably small sum at this point in the game)?