Slide the grid squares around so that the numbers end up in consecutive order from the top left corner.
On a touch screen, a tap does what a click does, and a long press what a right-click does (more ways to right-click).
Click on the arrows at the edges of the grid to move a row or column left, right, up or down. The square that falls off the end of the row comes back on the other end.
Right-click an arrow to slide the line the opposite way. You can also drag a square along its row or column: when you let go, the line slides by as many squares as you dragged it.
On the keyboard, the arrow keys move a cursor round the board. On one of the edge arrows, Enter presses it and Space presses it in reverse. On a square, Ctrl and an arrow key slides that square’s line, and the cursor goes with the square; Shift and an arrow key slides the line under a cursor that stays put. Enter or Space on a square locks the cursor into one of those two ways, so the plain arrow keys slide until you press it again.
Hint shows the next move rather than simply making it. Nothing in Sixteen is forced by logic, so the hint searches for a way to finish from where you are and tells you what each move is for.
Everything a step marks is part of the move it asks for, so the hint calls the square it lands on “the ringed square”.
Each step opens by naming the tile it is working on — “Working on tile 5:” — and ends by saying whether the move takes it to its final spot or is only setting up for a later one.
The search looks only so far ahead. When it cannot find a way to finish from your position, the hint says so rather than guessing: play a few moves of your own and ask again, or use Show solution….
These parameters are available from the ‘Custom type…’ option on the ‘Type’ menu.