How to Play Scale of Things: Rules, Scoring and Your First Run

Scale of Things asks one question again and again: how big is this, next to that? Each round puts two flat silhouettes on the same ground line, drawn to the same scale. One is labelled with its real size. The other is yours to resize until it looks right.

There is no timer, no typing and no daily limit. A run is five rounds and takes a few minutes. This guide covers everything a first run needs: what is on the board, how to set a guess, how the score works, and what happens after the fifth round.

The silhouette on the left is the reference. Its name and real size are written above it, as in "Giraffe 5 m tall". The silhouette on the right is the target, and the line over the board names it: "Scale Eiffel Tower to its true size". The target starts at roughly the reference's size, which is almost never the answer, so every round begins with you moving it.

Both shapes are silhouettes, filled in flat with no detail inside, so you judge by outline and size alone. Under the ground line runs a ruler, and a faint grid behind the shapes falls on the same ticks.

What is being measured depends on the thing, and the readout says which: tall, long, wide, across, or in area.

• Animals and vehicles are usually measured by length or height.
• Buildings, towers and statues are measured by height.
• Countries, states and lakes are measured by area.
• Planets, moons and stars are measured by diameter, which the game calls across.

The catalog holds more than 1,900 things: animals, dinosaurs and other prehistoric creatures, vehicles, everyday objects, buildings and landmarks, countries, states and lakes, and the bodies of space from asteroids to supergiant stars. Everyday things are paired with everyday things. Places and space bodies share their rounds, so a country can stand beside a moon.

There are several ways to resize the target, and you can mix them.

• Drag the round handle at the target's top right corner. Dragging anywhere on the open board above the ground does the same.
• Tap or drag along the ruler under the ground line. The ruler counts from the target's left edge.
• Pinch with two fingers on a touch screen, or turn the mouse wheel.
• On a keyboard, the arrow keys grow or shrink the target by 2% a press, or 10% with Shift held. Enter locks it in, and the plus and minus keys zoom.

As you resize, a small readout at the corner shows your guess as a figure ("19 m long"), with the imperial figure beside it on a wide screen. If you happen to know the number, you can dial it in exactly.

You can also pick up either silhouette and carry it. Lay the reference over the target, or stand it on top to count heights. Drop it near its place and it snaps back.

The zoom buttons give you up to three steps in and three out, each 1.5 times. Both shapes scale together, so zooming changes only the view, never your guess. Use them when the target is a speck or runs off the edge of the board. Anything drawn too small to see gets a little pointer over it so you can find it.

When it looks right, press Lock it in.

The real silhouette grows or shrinks out of your guess to its true size. A see-through copy of the target stays at the size you chose, so the gap between the two is plain to see, and two marks on the ruler show where you said and where it really is.

Above the board you get the round's verdict: a score out of 100 that climbs to its figure, how far off you were ("18% too big", "2.4× too small"), and a line such as "Really 27 m long, you said 19 m". A guess within 5% reads "Spot on!" instead. Then come the round's points, with its multiplier stamped on, and a comparison in familiar terms: a blue whale is "About as long as a basketball court". Press Next for the following round.

A guess is judged by the factor it is off by, never by the metres. Twice too big and half too small are the same mistake and score the same, which is why a guess at a whale is marked exactly like a guess at a beetle. Out of 100 for the round:

• Within 5%: 100, and "Spot on!"
• 15% too big or too small: 90
• 25% off: 81
• 50% off: 63
• Twice or half the real size: 37
• Three times or a third: 10
• Four times or more, either way: 0

The curve is gentle near the answer and steep further out. A careful guess and a perfect one are a few points apart. A careful guess and a wild one are most of the round apart.

Things measured by area have one twist. Your guess is scored on the outline's scale, its width, rather than its area, so an outline twice as wide counts as twice too big even though it covers four times the ground. In practice that makes places kinder than they look: a guess with double the true area is only about 41% too wide, and still earns 69.

The bar at the top of the card names the rounds as they come: Easy, Easy, Med ×2, Hard ×3, Hard ×3. Each round's score is multiplied by its number, so a perfect run is 1,000 points and 600 of them sit in the last two rounds.

The later rounds are harder in one specific way. Any thing in the catalog can turn up in any round, but the pairs drift further apart in size as the run goes on, and more and more often they are very far apart: three to six and a half times. That is where the zoom buttons earn their place.

A pip in the bar lights up for every round you land within 15%, and your best score sits beside the running total.

The end screen shows your total out of 1,000, a "New best" line if you beat your record, and the five targets in order with how far off each guess was and what it scored. From there you can press Play again for a fresh run or Share.

The share text looks like this: "Scale of Things 📏 742 / 1,000", then one line per round, such as "🎯 4% too big". The mark says how the round went: 🎯 within 15%, 📐 off by less than twice, 🔭 twice or more. It leaves out what you were sizing, because everyone is dealt a different five. On a phone, Share opens your share sheet; on a computer it copies the text, ready to paste.

Your best score is kept on the device you play on. Signing in is optional and keeps it with your account instead. The game also remembers the last 150 things it has dealt you, targets and references alike, and leaves them out while it has others to choose from, so runs stay fresh for a long time.

Before you touch the target, decide two things: bigger or smaller than the reference, and roughly how many times. Then count copies of the reference along the target instead of thinking in metres, check the other edge as well, and slow down in rounds four and five, where the multiplier is.

When you have a few runs behind you, our guide on how to get better at Scale of Things covers the habits that move a score from 500 to 800, and why we misjudge size explains the pull that makes almost everyone miss the same way.