Play Kakurasu Online Free

Kakurasu turns cell positions into arithmetic clues: a shaded cell contributes its column number to its row total and its row number to its column total. Published histories do not establish a reliable creator or first publication date, so no sound account should assign either one. The puzzle develops subset-sum reasoning and systematic elimination without demanding lengthy calculation. You compare target totals with possible position values, mark forced cells, and let each decision constrain a crossing line. Open a grid and solve the first exact sum now.

1. Read the position values along the top and left edges. In a 5 by 5 grid, columns contribute 1 through 5 to row clues, while rows contribute 1 through 5 to column clues. These labels supply weights, not coordinates to enter.
2. Choose a row clue and find subsets of its column values that equal the target. For a clue of 9, possibilities might include 4+5, 1+3+5, or 2+3+4. Cross out combinations blocked by known empty cells.
3. Shade a cell when every remaining combination for that line includes its weight. Mark a cell empty when no remaining combination includes it. Apply each decision to the crossing column immediately.
4. Recalculate residual clues rather than restarting each sum. If a row target is 11 and shaded cells already contribute 3 and 5, seek 3 more among undecided positions. This keeps the arithmetic small.
5. Complete the puzzle when every row and column reaches its printed total exactly. Confirm that shaded weights equal each clue and empty cells contribute nothing. No guessing should remain in a properly formed logic puzzle.

• A shaded cell contributes its column value to the clue at the end of its row. The same cell contributes its row value to the clue below its column.
• Each cell has one final state: shaded or empty. A mark affects two equations at once, so a legal row decision must also remain possible for its column.
• The shaded position values in every row must sum exactly to that row's clue. Exceeding a clue invalidates the line even if undecided cells remain.
• The shaded position values in every column must sum exactly to that column's clue. A completed row never overrides a conflicting column requirement.
• The puzzle uses logic based on finite subsets of positive weights. Zero clues force every cell in a line empty, while a clue equal to the full weight sum forces every cell shaded.

• Memorize extreme totals. On a five-cell line the full sum is 15. A clue of 14 means only weight 1 stays empty, while 13 means only weight 2 stays empty. Complement reasoning often works faster than listing large subsets.
• Calculate minimum and maximum residual sums. If three cells must still supply 8 and their weights are 1, 3, and 4, all three become shaded. If the largest available weights barely reach the target, each of them becomes mandatory.
• Find overlap among combinations. A target of 7 from weights 1 through 4 allows 3+4 or 1+2+4, so weight 4 appears in every solution. Shade that position even though the rest of the line remains unsettled.
• Propagate immediately across the grid. When row logic shades the cell at row 4, column 2, subtract weight 4 from column 2's residual clue. Delayed updates hide deductions and increase arithmetic errors.
• Use contradiction on a single cell only when direct sums pause. Assume the cell shaded, reduce both residuals, and test whether either line becomes impossible. If it does, mark the cell empty and record the reason.

• Aquarium: Aquarium also gives row and column totals, but region water levels govern which cells can fill. Kakurasu uses independent weighted cells instead. Play both to compare subset sums with geometric region deductions.
• Nonogram: Nonogram clues describe consecutive blocks, while Kakurasu clues describe weighted sums without requiring adjacent shaded cells. Both reward line-by-line elimination and immediate updates to crossings.

• Small equations produce visible progress. A single forced weight changes a row and a column, often triggering a chain that crosses the whole grid.
• The arithmetic stays concrete. Players add short lists of position values, compare subsets, and use complements, all while the grid records each conclusion visually.
• Difficulty grows through ambiguity rather than obscure rules. Larger boards create more possible subsets, yet the same residual sums, overlap checks, and bounds remain useful.

Play Kakurasu online for free and let the interface track cell states while you handle the logic. Shade a square, mark an excluded square, and compare the updated line with its target. The browser makes quick corrections easy and keeps every clue in view. Begin with an easy board to learn position weights, then try a harder grid where several subset combinations compete before their crossing clues separate them.

Kakurasu builds a complete logic puzzle from weighted row and column sums. Read the edge values carefully, reduce each clue after every shaded cell, and search for mandatory overlap among possible subsets. Avoid unsupported claims about its creator or date; the published record remains uncertain. The rules themselves need no mystery. Start a puzzle above, settle an extreme total, and carry that information into its crossing line until every sum matches exactly.

• Kakurasu FAQ and rules