Daily Sandwich Sudoku
The extra rule
A clue outside the grid is the sum of the digits between the 1 and the 9.
Find the 1 and the 9 in a line and add up everything sitting between them. That total is the clue printed outside. The 1 and the 9 themselves are not counted, and it makes no difference which comes first.
A 0 means the 1 and the 9 are next to each other. That is the most useful clue on the board, because it pins them to a pair of touching cells.
The biggest possible filling is 35, which is every other digit, so a 35 forces the 1 and the 9 to the two ends of the line. Large clues squeeze them outward and small ones pull them together.
Controls
Click a cell and type a digit, or use the pad. Space toggles pencil marks. Arrow keys move. Progress saves in this browser as you go, so you can come back to the same puzzle later today.
Solvable Without Guessing
Every puzzle here was generated and then handed to a solver that is only allowed techniques a person can use. If it could not finish the grid without a guess, the puzzle was thrown away rather than published. That also makes the answer unique, because every digit it placed was forced.
More to Play
There is also a kropki sudoku, a xv sudoku, a greater than sudoku, a nonogram with hand drawn pictures, and 2048. All of them are on the games page, and the solvers for real objects are on the puzzle tools page.