Here are two neighbors puzzles, a type which features on next weekend’s Dutch round of the WPF Puzzle GP. This time there is plenty of practice material, see Richard’s comment on the GP forum.

I made the second one first, but it appears I broke or imagined some of the logic. It does seem to have turned out unique. Usually I wouldn’t post it, but maybe it’s good practice for dealing with an impenetrable puzzle? If you find a nice way through, do let me know.

Rules Place a digit between 1 and 3 in every cell, such that each row and column contains exactly three copies of each. A cell is shaded if and only if the digit that it contains is different from all orthogonally adjacent digits.