Every pair of opposite cells along the Arrowdrome must be exactly one of the following:

- The cells have the same number.

- The difference between each cell and the one it points to (circle - arrow) is the same.

This difference is NOT absolute, i.e. A-B≠B-A.

Some arrows' differences are specified.

The white circles in between four cells states digits that must go in those cells, in some order.