Normal Sudoku rules apply.

Sandwich: The digits outside the grid besides a row or column indicate the sum of the digits between 1 and 9 in that row or column.

Little killer: The numbered arrows outside the grid indicate the sum of the digits in the corresponding direction. Digits can repeat in the direction of the arrow.

Kropki: Adjacent cells marked with a black dot must have a ratio of 2.

XV: Adjacent cells marked with a V must sum to 5 and those with an X must sum to 10.

Minimize: The cell marked with the 4 arrows pointing inwards must be lower than all orthogonally adjacent cells.

Between: The digits on the line must be between the digits on the circles.

Odd/Even: Digits on a circle must be odd; Digits on a square must be even.

Greater Than: The greater-than sign is open towards the greater value between two cells.

Killer cages: The sum of all digits in a cage must match the small number in its corner.

Thermometer: Digits must be increasing along a thermometer, with the smallest digit on its bulb.