You have a standard chessboard $(8\times8)$.
And you have a lot of numbers from the set $[-1, 0, 1]$.
You have to place one number in each square so that the sums on each row, column, and the two diagonals are different.
To clarify, they must all be unique, regardless of direction (not just different among rows or columns).
If you can do that, what's the strategy?
If not, why?