Moderator Action: This post and a few below were moved/copied from this thread to create this one (Gedemon) You're completely right, my bad. What I mean is rather the base resources, like Wood and Stone, being converted to other things rather than what is needed for Construction (usually Materiel). In screenshot below, Baghdad produces Wooden clubs and Timber amongst other things, while efficiency of Builder production is low. Spoiler Screenshot : Another thing I've noticed just now is that Builders and Settlers keep appearing on and disappearing from the list of production choices. Some turns I can see them and pick them in the list, other times they are completely missing. In the screenshot game above, where I started with a Carpenter, Builders appeared early. But in another game where I started with a Stonemason instead, the Builder and Settler rarely appeared in my list. When I'm producing buildings, and other units, the "Resources required per construction turn" stays the same, regardless of efficiency. But when I'm producing Builders, the Materiel required per turn fluctuates every turn. Is it supposed to work like that?