Normal Sudoku rules apply and all variants are standard.
Place the digits 1-9 once each in every row, column and box.
Killer: Digits in a cage cannot repeat and sum to the number in the top-left corner.
Thermo: Along thermometres digits much increase from the bulb.
Arrows: Digits along an arrow sum to the number in the connected circle. Digits may repeat along an arrow if allowed by other rules.
Kropki: Digits separated by a white dot much be consecutive. Not all white dots are necessarily given.
X Sums: Digits separated by an X sum to 10. Not all X's are necessarily given.
Solution code: Row 9 digits, left to right
on 14. July 2026, 20:28 by geronimo92
X Sums is not the right expression to use in this ruleset !
on 22. June 2026, 00:48 by Myfyr MJ
Very nice and approachable for a 4 star difficulty puzzle - maybe reduce difficulty to 3 stars?