Originally posted by Phoenix-D: "Well, i could build a system shield facility to stop it but i'll do both: build a shield and construct the 2 ringworlds:-)"
you'll have to scrap the shield before triggering the ringworld..otherwise the final step will fail.
Phoenix-D
This is incorrect.
System Shield will prevent warp closing/opening and every form of star destruction. However the construction of ring-/shereworlds is not impeded.
ringworld construction as a weapon:
So your enemy has this trinary system full of solar collection array (or whatever those resource thingies are) planets, and has a system grav shield. To take the whole thing out of commission, all you have to do is make his three stars into ringworlds!