Leeds wrote:Do I have to have Trench Doctrine to enable Trenches?
Yes. Firepower doctrine is required to entrench troops. The trench level is then upgraded by technologies.
Leeds wrote:What are the impacts and timelines for the other Doctrines?
Firepower doctrine allows the research and commitment of Combat Doctrines (Heavy Bombardment, Flash Bombardment, Rolling Barrage, etc.), at a rate of one doctrine per nation per grand offensive: so, provided each major nation can attempt one grand offensive per year, she can attempt the research and commitment of a new doctrine for the entire year. In addition, allied major powers can attempt a joint research of the same doctrine, as well as they can try with different doctrines (i.e.: France can try one doctrine on the west, Russia another doctrine on the east).