Somewhere in this cellar, one bottle is already poisoned — nobody knows which. Choose who sips from each bottle (share bottles as freely as you like); overnight, every sipper of the bad bottle dies. Find the poisoned bottle.
One marble is secretly heavier than the rest. Use the balance scale to find it in as few weighings as you can.
Ferry the fox, the goose, and the beans across the river. The boat holds you plus one passenger — and whatever you leave behind must not become a meal.
Four people must cross a rickety bridge at night with one flashlight. At most two cross at a time, a pair moves at the slower one's pace, and the flashlight has to come back for the others. Get everyone across in as little time as you can.
Each dwarf holds a sack. One bulges with gems 💎 — the other two are full of dung 💩. Pick a sack; a dwarf opens a losing one; then decide — keep yours, or switch?
No measuring marks — just two jugs and a tap. Fill, empty, and pour between them until one jug holds exactly the target.
Take as many stones as you like from a single row — but only one row per turn. Whoever grabs the very last stone wins. The computer plays perfectly; can you find the trick to beat it?
Move the whole stack to the right-hand peg. One disk at a time, and never a larger disk on a smaller one. Click a peg to lift its top disk, then click where to drop it.
Tap a tile and it flips — along with its four neighbors. Turn the whole board dark. Sounds easy; the neighbours are what make it a puzzle.
Two eggs and a tall tower. Click a floor to drop an egg: find the highest floor an egg can survive. A broken egg is gone for good — and the tower always answers with your worst case, so only a clever plan finishes fast.
Beyond the green glass door, some things may pass and some never will — and there is a rule. Quiz the doorkeeper with any word you like; when you think you've cracked it, prove it by judging eight words in a row.
Out in deep space the numbers obey a strange law: 5 is 4, 9 is 4, 23 is 11 — and 4 is cosmic, forever. Ask the stars about any number; when you think you've decoded the law, prove it by answering eight in a row.
A secret code of colors — duplicates allowed. After each guess the codemaker answers in pins: a gold pin for a right color in the right spot, a hollow pin for a right color in the wrong spot. Crack the code before the guesses run out.
The name of the game is Petals Around the Rose, and the name is a mighty clue. Roll five dice as often as you like — the dealer scores every roll. When you think you see it, prove it by scoring eight rolls in a row yourself.
Inside the room: 100 boxes hiding the numbers 1–100, shuffled. Each prisoner may open 50 boxes looking for their own number; then the room is reset for the next prisoner. If all 100 succeed, everyone walks free — one failure dooms them all. Step inside yourself, or pick a strategy and run the night.
Place the knight on any square, then keep making knight moves onto squares you haven't visited yet. Land on every square of the board exactly once — corner yourself, and the tour is over.
Slide the tiles into order, 1 onwards with the gap in the last corner. Click any tile in the gap's row or column and the whole run shifts over at once.
A hidden picture, described only by numbers. Each clue counts the runs of filled cells in its row or column, in order. Click to fill, click again to mark a cross, once more to clear. Satisfy every clue to reveal the picture.
Atoms are hidden in the box. Fire rays in from the edge and read how they come back: a ray that strikes an atom head-on is a hit; one that passes a corner is bent away; some bounce straight back as a reflection; the rest exit elsewhere, tagged with a matching number. Deduce where every atom hides.
Three missionaries and three cannibals must cross the river. The boat carries one or two, and someone must row it. But if cannibals ever outnumber missionaries on either bank, the missionaries are eaten. Get all six safely across.
Get all eight across on a raft that holds two. Only the three grown-ups — 👮 cop, 👩 mother, 👨 father — can row. Watch the feud: the 🦹 thief robs anyone left without the cop, the father can't be left with a daughter unless the mother's there, and the mother can't be left with a son unless the father is.
Three married couples must cross the river in a boat that seats two — anyone can row. But the husbands are jealous: a wife may never be in the company of another man unless her own husband is right there too. Get all six across. Couples share a number.
An army must cross the river. The only boat is a tiny canoe that carries either one soldier, or one or two boys — never a soldier and a boy together. Two boys are here to help. Ferry every 💂 soldier to the far bank.
Every hole holds a peg but the centre. Jump a peg over a neighbour into the empty hole beyond, and the jumped peg is removed — straight lines only. Clear the board down to a single peg; finish in the centre for the perfect solve.
Pick a sequence of three coin flips. The computer picks its own, then a fair coin is flipped until one sequence appears — that player wins the round. A fair contest? Play a while and watch the tally. The computer always chooses second…
Drop your discs and line up four in a row — across, down, or diagonally — before the computer does. On Perfect it never blunders and pounces on any mistake. You're red and move first; beat it if you can.
Fill the grid so every row, every column, and every 3×3 box holds the digits 1 to 9 exactly once. The clues fix the rest — there's just one solution. Tap a cell, then a number; conflicts light up red.
Clear every safe square. Each number tells you how many mines touch that square; use them to deduce where the mines hide and flag them. Your first click is always safe — after that, one wrong step and it's over.
Slide all the tiles one way; equal tiles that bump together merge into their sum, and a fresh tile appears each move. Keep merging up the powers of two until one tile reads 2048. Use the arrow keys, the buttons, or swipe.
You're the warehouse keeper. Push each crate 📦 onto a marked spot — you can only push, never pull, and just one crate at a time. Shove a crate into a corner and it's stuck for good. Use the arrow keys, the buttons, or swipe.