Hvordan spille XV Sudoku
X mellom celler betyr at de summerer til 10; V betyr at de summerer til 5
Reglene
Standard Sudoku-regler gjelder: fyll hver rad, kolonne og 3×3-boks med sifrene 1–9, hver forekommer nøyaktig én gang.
XV Sudoku (også kalt Ten-Five Sudoku) plasserer X- og V-markører mellom tilstøtende celler. En X betyr at de to cellene summerer til 10; en V betyr at de summerer til 5. Mange XV-puslespill bruker den negative begrensningen: fraværet av en markør garanterer at paret verken summerer til 10 eller 5. Kombinert med standard Sudoku gir dette svært stramme begrensninger på tvers av rutenettet.
For hvor denne oppgaven kom fra, hvordan den sammenlignes med relaterte varianter og en strategioppsummering, se vår XV Sudoku variantoversikt.
På et øyeblikk
Hvordan løse XV Sudoku
Vanlige spørsmål
Hva er XV Sudoku? ▾
XV Sudoku is a variant where X and V symbols appear between adjacent cells. An X marks two cells that sum to 10. A V marks two cells that sum to 5. Standard Sudoku rules apply, and — critically — all X and V relationships are fully marked: if there is no symbol between two adjacent cells, those cells are guaranteed not to sum to either 10 or 5.
What pairs sum to 10 (X)? ▾
The valid X pairs are: 1&9, 2&8, 3&7, 4&6. Note that 5&5 sums to 10 but standard Sudoku uniqueness rules prevent two 5s from being adjacent in most cases. The X constraint immediately limits each marked cell to a small set of candidates.
What pairs sum to 5 (V)? ▾
The valid V pairs are: 1&4, 2&3. Only four digits can ever appear in a V cell: 1, 2, 3, or 4. This makes V markers particularly powerful for restricting candidates in the lower half of the digit range.
How does the no-symbol constraint work? ▾
All X and V relationships are shown — if two adjacent cells have no symbol, their sum is guaranteed to be neither 5 nor 10. This negative constraint eliminates candidate pairs from unmarked cell boundaries and is often as useful as the explicit symbols.
Is XV Sudoku hard to learn? ▾
The rules are simple to memorise. The challenge is applying both the positive (X, V) and negative (no symbol) constraints simultaneously across the entire grid. Easy puzzles are very accessible; expert puzzles require exhaustive tracking of all adjacent-cell relationships.
How long does XV Sudoku take to solve? ▾
Easy puzzles take 8–15 minutes. Medium puzzles run 15–30 minutes. Hard puzzles average 30–60 minutes and expert puzzles often exceed 90 minutes. The no-symbol negative constraint is the most time-consuming to apply systematically across a densely marked grid.