The Queen’s Gambit is the easiest puzzle to solve but gathering the materials to purchase the book from Omi, Mistress of Puzzles, is a lot of work.
Eight noisome spores are required to purchase the puzzle book from Omi. The spores can be bought from Ezial on the Fetid Planes in Serratos (11506, 4043, follow the road east from the Hollow porticulum). Each noisome spore costs 10 mutated spores which can be found in the area around Ezial. You’ll need 80 mutated spores altogether.
The Queen chess piece that ports you up to the puzzle is located at 4828, 8678 near The Academy porticulum in Kingsward. Click on the piece and it will take you to the puzzle location. Once there, place all eight queens on the chess board without any piece being able to take another piece. A solution to the puzzle is pictured below
The dimension item rewarded by this puzzle is the Queen Chess Piece.