Missing Piece is a pattern puzzle about a sheet of monster stickers with one sticker missing. Each sticker shows a little crew of monsters, and everything about them follows a rule: their species, how many there are, their hats, their faces, and later whether they’ve tipped over. Read the rows, read the columns, and pick the sticker that finishes the sheet. The right one slaps into place and the whole crew cheers. The wrong one blows a raspberry at you.

It starts with one thing changing at a time and four stickers to choose from. Get them right and it climbs to four things changing at once and six choices. Then the mash-up shows up and the monsters start adding up.

Missing Piece is part of Unrot, a series of short games that each put one mental skill to the test: memory, attention, speed or logic. Zero brainrot.

How to play

Look at the 3×3 sheet. The bottom-right sticker is missing.
Find what changes along the rows and down the columns: species, count, hats, faces, poses.
Pick the sticker that fits the gap. Tap it, press its number (1–6), or use the arrows and Enter.
A wrong pick costs 5 seconds and your streak. The run lasts 90 seconds.
In a mash-up, the monsters on the first two stickers add up to the third, shown with + and = signs.

Scoring

Every right pick scores 100 points plus 50 per level, times your streak multiplier (×1 up to ×5).
Right picks move you up a level (more things change, more choices); a wrong pick moves you down one.
Play the Daily for one scored run on the same sheets as everyone else, and keep your Unrot streak alive.

Tips

Go one attribute at a time. Settle the species, then the count, then the hats. Each one has its own rule.
Check the bottom row first: two of its three stickers are right there, so it usually tells you the most.
“Each once” rules are easy to spot: if a row has a cap, a crown and a party hat, the last row needs the one that’s missing from it.
In a mash-up, only the count adds up. Colors, hats and faces still follow their own rules.

FAQ

Is Missing Piece free?

Yes. Missing Piece is free to play in your browser on desktop and mobile, with no download and no account.

How does Missing Piece work?

You get a 3×3 sheet of monster stickers with the bottom-right one missing. Every row and column follows a rule: the same color along a row, one more monster each step, each hat once per row, and so on. Work out the rules and pick the sticker that fits the gap from four or six choices. It's a matrix puzzle, the classic 'what comes next' kind, with more monsters.

Is there always exactly one right answer?

Yes. Every sheet is checked by a solver that reads the eight visible stickers, tries every rule a player could reasonably see (constant, step by step, each one once, adding up), and throws the sheet away unless all of them agree on one answer and only one choice matches it. The wrong choices are close on purpose, and they're balanced so you can't find the answer by picking the choice that looks most like the others.

What is the mash-up?

From the third level, or after 45 seconds, some sheets add up: the number of monsters on the first two stickers of a row (or column) adds up to the third. The sheet shows + and = signs between the stickers when it happens. The other rules still apply on top.

How does scoring work?

You have 90 seconds. A right pick scores 100 points at the first level and 50 more for each level up, times your streak multiplier, which climbs from ×1 to ×5, one step every two right picks in a row. A wrong pick resets the multiplier, drops you a level and takes 5 seconds off the clock. The Daily gives everyone the same sheets once per day.