Once a game is in progress, click on a tile in one of the corners around the board and drag the tile onto a square on the board. You can either hold down the mouse button while you drag and let go when the tile is where you want it, or you can click once and drag the tile, then click again to place it.
Tiles in any ring can not match their neighboring tiles in the same ring by color or by symbol. Tiles in the inner rings, and the tile in the “hot spot,” must match one of the connecting tiles of the next outer ring by color and the other by symbol.