🎮 Non-Competitive Games Tools

Play against a real search-based computer opponent at three depths, or against someone else on the same device — with the fact that the game is solved.

Play Reversi against a search-based computer at three depths, or against someone on the same device — with why holding corners beats holding discs.

Conway's cellular automaton — draw your own cells or load a glider, blinker or R-pentomino and watch what four simple rules produce.

An idle game with the geometric series done properly — bulk prices use the closed form, and "buy max" is the same series solved for the count.

Say a word that connects to the last one, before the clock runs out. No repeats — and plurals count as the same word, checked against a real dictionary.

Turn any picture into a jigsaw of 12 to 192 pieces and solve it by dragging — your image is read in the browser and never uploaded.

Paint sand, water, oil, stone, plant and fire and watch them behave. Sand heaps, water spreads, oil floats, fire burns and smoke rises.

Zoom into the Mandelbrot set to the limit of double precision, or switch to Julia sets. Five palettes, named landmarks, and a save button.

Fill in the blanks and read back the nonsense. Six stories built in, a builder for your own, repeatable blanks, and “a” and “an” fixed automatically.

Full rules with compulsory captures and multi-jumps. Play the computer, someone on this device, or a friend on another device via a shared code.

Play against an unbeatable computer or a friend — with the reason a perfectly played game can only ever end in a draw.

Play three opponents — one random, two that model your history — and watch a live readout of how predictable your throws have actually been.

Five in a row on a 15x15 board. An open four cannot be blocked, which is the fact the whole game is organised around.

Sow stones anticlockwise; land in your store and go again. That one rule is why Kalah is a proven first-player win.

Draw a line, complete a box, go again. The game is decided by who is forced to open the last chain, not by who grabs boxes early.

Place, move, then fly. Solved as a draw in 1993 — so every decisive game comes from a mistake rather than the opening.

Nine boards, and your move dictates where your opponent must play. Winning a small board is often the wrong idea.

The area test rejects an impossible silhouette in one pass and can never confirm a possible one. Two shapes here prove it.

Everyone is taught to hold at 20. Solved properly, that is optimal in 557 of 10,000 positions — five per cent — and it gives away four points.

A local rule solves it optimally with no planning — but reverse one bit of it and it never solves the puzzle at all.

Which amounts can two unmarked jugs measure? Exactly the multiples of their gcd — verified by search over 225 jug pairs, zero mismatches.

Wolf, goat and cabbage plus missionaries and cannibals — with the search that shows four of each with a two-seat boat is impossible.

A two-player cannon duel with wind, plus the firing-solution maths: every level target has two angles that sum to exactly 90 degrees.

Play Three Men’s Morris against a perfect engine, and see why one of its four rule sets is a first-player win while the other three are draws.

Play the press-your-luck dice game, with the exact bust chance for all 165 trios of columns counted over every one of the 1,296 rolls.

Land the module by hand, and see why fuel burned equals gravity times flight time exactly — so minimum fuel is the same thing as minimum time.

Connect all three sides of a triangle. A filled Y board always has exactly one winner — checked over every colouring of 2,131,008 boards.

Play the visibility logic puzzle, and see why its clue numbers are Stirling numbers and why most grids cannot be made into a puzzle at all.

Play the binary logic puzzle, and see which of its three rules actually does the work — the answer changes as the grid fills and again as the board grows.

Join each pair of numbers with a path that covers every cell — and see why the obvious way to generate these puzzles fails, measured rather than asserted.

Sudoku played with the nine letters of a word — and a count of how many such puzzles can exist at all, which is smaller than the number of words that qualify.

Play the party dice game at a full table, with exact odds. It contains no decisions at all — and yet the seat you sit in still changes your chances.

Play the push-your-luck dice game, and see the exactly solved stopping rule — which depends on how many red dice are left, not just on how many brains you hold.

Keep a Qwixx score sheet, and see the exact cost of skipping a number — which falls as the row degrades, the opposite of what most players assume.

Work out where the 1 and 9 can sit from a sandwich clue — and see which two totals are impossible, and why they are impossible for the same reason.

Look up every digit combination for a Killer Sudoku cage — and see which 43 size-and-sum pairs fix the digits outright, which is the opening of every puzzle.

Play sudoku with nine irregular regions instead of nine boxes — which pins one answer with about 16 clues where a standard grid needs 24.

Play LITS — and see why "no square piece" is not a rule at all: the square IS a 2x2 block, which LITS already forbids everywhere.

Play Hex against a computer that plays 4x4 perfectly — and see the no-draw theorem counted out over all 65,536 ways to fill a board.

A one-button flyer where every level is provably flyable — because the textbook physics formula overstates the climb by exactly one frame of gravity.

Place towers on a path and see the geometry — damage is just path length in range, a straight caps at 2r, and building on the corner is a mistake.

Play Hearts against three opponents, plus the measurement: watching for a moon shot stops three in five, and half of what survives was never stoppable.

Visit every square once, plus the measurements: half an odd board cannot start a tour, and the tie-break is most of Warnsdorff’s rule.

Find the matching symbol, plus the mathematics: one rule fixes the whole deck, the retail one is two cards short, and a seven-symbol deck cannot exist.

Play a spymaster and pick the number, plus the arithmetic: a clue has a ceiling your accuracy sets, and the numbers that lose the game are divisors of eight.

Dodge a field of bullets, plus the geometry: covering a screen takes twelve to sixteen times more bullets than covering its area does.

Thread a shifting tunnel, plus the physics: flying faster costs you no reaction time at all — it costs you the distance you must see ahead.

Watch three collision resolvers on one table: the correct one never creates energy, and the two classic bugs fail in completely different ways.

Guess a hidden word letter by letter, plus the measurement: a third of the dictionary can never be pinned down, and the plural is why.

Put a list in order, scored three ways at once — because counting correct positions gives zero to an answer that is only offset by one.

Run and jump, plus the finding: the timing window gets WIDER as you speed up, so an endless runner does not get harder because of the jump.

Fly a ship with no brakes, plus the physics: stopping time is linear in speed and stopping distance is quadratic, which is why you always overshoot.

Bounce a putt off the wall, plus the geometry: a bank shot is never shorter than the direct line, and helps less the bigger the obstacle.

Spot the odd number out, with every puzzle checked against the whole property list — because the naive way to build one is ambiguous 98% of the time.

Lob a projectile over a wall, plus the arithmetic: 45 degrees is only best on level ground, and your height matters four times more than your aim.

Rotate pipes to connect the corners, plus the measurement: a tee is exactly as flexible as a cross, and a bigger board is easier to connect.

Play Scopa, plus the arithmetic: primiera is scored on its own ordering, and taking the most cards loses three of the four points.

Play Durak, plus the arithmetic: a trump attack is twice as hard to answer, and the card you defend with can extend the attack against you.

Play Yajilin, plus the measurement: the arrow clues leave thousands of shadings standing and the loop condition does almost all the solving.

Play Country Road, plus the measurement: the loop traces a Hamiltonian cycle of the regions, which explains most of solvability but never all of it.

Play Cheat against three opponents, plus the arithmetic: a lying claim of four cards can always be disproved by somebody at the table.

Count Gin Rummy deadwood by searching every meld combination, and see the hands where taking the biggest meld first gets it wrong.

Explore the Euchre bowers: naming trump moves a jack between suits, so the deck becomes 7, 5, 6 and 6 rather than four suits of six.

Play Abalone, plus every pushing configuration enumerated: exactly three ratios can push, and a line of three cannot be pushed by anything.

Play Fox and Geese, plus the board solved exhaustively: four geese is the fewest that can ever win, and it wins from 84 positions in 101,745.

Work out backgammon doubling-cube decisions, with the 25 per cent take point derived rather than quoted — and why the live cube moves it.

Play Onitama against the computer, plus the card geometry: every card you hand over has exactly the opposite forward bias for your opponent.

Play Halma against the computer, plus measured jump-chain lengths and why the longest one found keeps growing with the sample.

Play Hnefatafl (Brandubh) with the disputed rules as switches, plus measured win rates showing one rule swings the game 80 points.

Play Santorini against the computer, plus the measured answer to whether you can be walled in — you can, and the board is mostly empty when it happens.

Play TwixT against the computer, plus the measured crossing geometry: all eight of a peg’s links fit, but each link rules out nine others.

Play air hockey, plus the exact bank-shot mirror rule and the measured reason banking costs you precision and time without beating anyone.

Play Lines of Action, plus the measured reason capturing is usually a mistake — and the one rule that flips that answer completely.

Play TriPeaks solitaire, plus solved proof of what the king-to-ace wrap rule is worth: it removes 89% of the impossible deals.

Play Havannah in your browser, plus a measured answer to which of its three winning shapes actually happens — and why the ranking inverts.

Play Konane, Hawaiian checkers, against the computer — plus solved 4x4 and 5x5 boards showing the opening lift decides the game.

Play Pyramid solitaire, and see the solved win rates: one pass through the stock clears 5% of deals, three passes clear 68.5%.

A vertical bouncing platformer, plus the measured reason wrapping the screen edges is what makes it winnable rather than a cosmetic touch.

Play Shakashaka in your browser, plus the measured reason its region rule is really a test you can run at a single corner of the grid.

Play Pong two-player or against the computer — and see why flat mirror bounces make the game unwinnable, measured rather than asserted.

Intercept incoming missiles by aiming where they will be — and see why a slower interceptor can only catch things heading within arcsin of the speed ratio.

Play Chomp against a perfect opponent — the first player always wins, the winning move is always unique, and no formula for it is known.

Play Nim and misere Nim against a perfect opponent — and see exactly where the two games differ: only when every pile is down to one counter.

Play Heyawake — and see why the rule everyone forgets is load-bearing: drop it and 362 uniquely solvable layouts collapse to just 20.

Play Norinori — shade two cells per region so every shaded cell sits in a domino. Those dominoes cross region borders far more often than you would guess.

Play Aquarium — water finds its own level in each tank. One deduction settles six more cells, which is why row and column totals are enough.

Play Star Battle — two stars per row, column and region, none touching. That rule alone throws away all but one arrangement in 9.4 million.

Bounce a laser through a grid of mirrors. A beam can never be trapped — checked over 192,000 traces, including boards with a mirror in every cell.

Play Clobber against a perfect opponent. Every move removes a stone, so the game lasts at most one move fewer than the stones on the board.

Tip a 1x1x2 block across a grid of holes. One square costs three moves and three squares cost two — the nearest square is not the cheapest.

Pitch one tent beside every tree with no two tents touching. A board holds at most a quarter of its squares — and a 6x6 holds no more than a 5x5.

Shade cells so every row and column hits its number — and see why exactly six clues out of the whole range settle a line on their own, at any size.

Play Breakthrough against a computer, and see why it has no repetition rule: pawns only move forward, so no position can ever recur.

Pour colours until every tube is one shade — and see why one spare tube leaves most deals impossible while two solved every fill tried.

Shade cells so every number sees exactly that many — and see why the checkerboard, the best possible packing of black cells, is illegal.

Play Pentago against the computer, and see why its 288 opening moves are really only six — and when the compulsory twist nearly costs you a win.

Play Quoridor, and see why the no-blocking rule is the whole game: without it three walls would win outright, yet it refuses barely 1% of placements.

Find the false coin in three weighings, and see why the puzzle says twelve when the counting bound says thirteen — a parity argument, not caution.

Scramble a 2x2 cube and get a provably shortest solution — plus why God's number of 11 describes only 0.072% of the puzzle.

Play nonograms that always have one answer and never need a guess — plus the measurement showing sparse pictures do not make puzzles at all.

Play Game of the Amazons against the computer, and see why a game with a hundred times chess's opening width is still over in 92 moves.

Play Order and Chaos against the computer, and see why every board small enough to solve exactly goes to Order.

Drag points until no lines cross. Every puzzle is built from a crossing-free layout — and the obvious method clears 95% of the mess then stops dead.

Play Light Up puzzles that never need a guess — plus the measurement showing the rule every tutorial teaches first settles 0.3% of the board.