There is a hill. And one person starts by building something on the hill.
The next poster writes how they will destroy the building on the hill that was made by the previous poster and will then make a new building to replace the building on the hill (only one building per hill and no making new hills )
The next poster will do the same.
Got it? no? here is an example:
Person 1: I build a hospital on the hill Person 2: A disease, starting from a patient, spreads and kills everyone in the hospital. The hospital was then taken down. I build a fort on the hill Person 3: I bomb and destroy the fort with mortars. I then make a school over the rubbles.