Hi All, enjoying getting to know the game, 1 question and apologies if its been asked before, i can't seem to get the search to work within the forum, anyway here goes,.... how do you increase the hit points/damage on  the catapults as they come out with an attack of 0!! do you have toi buy it ?? as i can't seem to get that to work or is there a combination of shops/indusstry trhat has to be built first or is it research?? can anyone let me know, much appreciated and thanks in advance..

slarti