Calculus is a strategic connection game between black and white. Players alternate pushing stones of their colour onto the board. There is no grid - stones may be pushed to anywhere on the board. When touching stones enclose an area the majority of stones on the perimeter of that area decide who controls the area. It is illegal to create an area which has the same number of black and white stones on its perimeter. Stones that are part of the perimeter of an area are immobilized, but the rest may be pushed again instead of introducing a new stone. The winning player is one who connects their edges of the board.
There is no standard shape of board and no standard stone. You can use a tree stump and real stones if you wish. I prefer to use circular stones.
Calculus may be reproduced for non-commercial purposes.
Power Point files with the rules and a sample game are posted in the files section of this page. (An additional rule up for discussion is posted in the forum: "Arguements about touching".)