What does a queen rule out in Queens?

A queen rules out every other tile in its row, its column and its colour, plus the eight tiles touching it, including the diagonal neighbours. Marking those tiles as soon as you place a queen is the most useful habit in the game, because the marks show which row, column or colour has run out of options.

One queen, many tiles

This single queen rules out 9 of the 25 tiles: the rest of row 1, the rest of column 1, and the tiles touching it.

The four things to mark

1. Its row. Each row has one queen.
2. Its column. Each column has one queen.
3. Its colour. Each colour has one queen.
4. The tiles touching it. Up to eight, including the four corners. The corners are the ones people forget.

Queens is not chess

A chess queen attacks along the whole diagonal. In Queens only the tiles directly touching are ruled out. Two queens can sit on the same long diagonal as long as they aren't neighbours.

Let the game do it

On this website the tiles a queen rules out are marked automatically, and you can switch that off with the Auto-mark box if you prefer to do it by hand. In the Queens Court app, automatic marking is an upgrade called Royal Sight.