Logic Puzzles — 8 tools
Hand-picked classics where the goal is the reasoning. Each tool here shows the deduction trail so the solving process is auditable, not just the final answer.
Minesweeper Logic Helper
Click a cell on a small board to enter the revealed number. We flag every cell that is provably forced, given those clues.
Click cell to edit. Type digits 0–8 in the prompt that appears. State -1 (mine) on a cell if you've flagged it.
Mastermind Decoder
Guess the secret code. Our best-next-guess engine uses Knuth's minimax algorithm to minimise the worst-case expected search size.
Your guess
Suggested next guess
History
Einstein-style Logic Grid Builder
Set up a 5×5 logic grid (e.g. 5 houses, 5 colours, 5 pets). Type your clues; the solver marks X and ✓ until each row has exactly one ✓.
Clue phrases recognised: "X is Y", "X is not Y", "X is left of Y", "X is right of Y", "X is next to Y", "X next to Y".
Knights & Knaves Solver
Classic "knights always tell truth, knaves always lie" puzzles. Type a few statements; solver assigns types and answers every question.
Add people
Add a statement
How the solver works
We encode each person as a boolean (knight=1, knave=0). Each statement becomes a clause. The solver is a tiny DPLL engine running through 2ⁿ assignments for n ≤ 8.
Self-referential statements ("I am a knave") lead to unsatisfiable assignments; the solver flags them.
River Crossing Solver
Wolf, goat, cabbage (classic) plus two custom presets. Solved by BFS over states, with rule-violations flagged.
Tower of Hanoi Visualiser
See the optimal move sequence. Each move prints "move disk from P₁ to P₂" so the recursion is visible.
N-Queens Visualiser
Place N queens on an N×N board so none attacks another. Solver uses backtracking with pruning; you can watch the recursion unwind.
Argument Grader
Paste your self-written argument. We score it across 5 axes: clarity of claim, premise sufficiency, counter-example anticipation, hedging, and tone. Each axis 0–5.
What the rubric values
- Clarity: a single, stated conclusion.
- Premise sufficiency: at least one observation or data point supporting the claim.
- Counter-example anticipation: explicit acknowledgement of limits or opposing evidence.
- Hedging: words like "may", "could", "in many cases" where certainty is unjustified.
- Tone: absence of personal attack / absolute language.