Hmmm... You have a point, but I think "diagonally forward or orthogonally" is awkward. I think a comma clears it up: "Gold: steps one square orthogonally, or diagonally forward". Or if you want to be certain, at the cost of some redundancy "Gold: steps one square orthogonally, or one suqare diagonally forward". Your wording is also clear, but sounds awkward to me, although I'm not exactly sure why.
Hmmm... You have a point, but I think "diagonally forward or orthogonally" is awkward. I think a comma clears it up: "Gold: steps one square orthogonally, or diagonally forward". Or if you want to be certain, at the cost of some redundancy "Gold: steps one square orthogonally, or one suqare diagonally forward". Your wording is also clear, but sounds awkward to me, although I'm not exactly sure why.