GUT/CHECK
SYS NOMINAL · CHECK #142
PLAY TODAY'S CHECK
DAILY INSTINCT CALIBRATION

GUT/CHECK

Five instruments. Sixty seconds. One verdict.

A daily perception and estimation game, in the spirit of Wordle. Five challenges by feel: judge angles, fill levels, midpoints, counts, and hidden timers. Everyone on Earth gets the identical five each day. Score out of 500, get your rating, challenge a friend. How sharp is your gut, really?

PLAY TODAY'S CHECK
PLAY A FRIEND SEE ALL 100 INSTRUMENTS
≈60 SECONDS 5 ROUNDS NO ACCOUNT
PRIMARY GAUGE · CALIBRATION READOUT LIVE
000 500
TODAY · SCORE
···
VERDICT
···
STREAK
00
00 What It Is READ FIRST

What is GUT CHECK?

GUT CHECK is a free daily puzzle game, a daily ritual in the spirit of Wordle. Each day, five instruments are drawn from a pool of 100 and dealt to every player on Earth in identical form, seeded from the date. Each one tests a different sense: draw an angle by feel, fill a vessel to a target percentage, find a line's true midpoint, count dots from a one-second flash, stop a hidden timer. The 100 instruments span six senses (geometry, proportion, time, perception, number, and motion), so it plays like a daily angle or estimation game, but broader. A full run takes about sixty seconds. Every round scores 0 to 100, the five sum to a score out of 500, and the needle settles on a verdict from RECALIBRATE to MACHINE. It runs on any phone or computer and installs as an offline app, with nothing to download. And unlike trivia or word games, GUT CHECK tests raw perception, not knowledge, so there is nothing to study.

A solo project by Amrudin Catic. It runs entirely in your browser, needs no account, and stores nothing on a server.

How a daily check works

  1. Five instruments are dealt from the bank of 100, the same five for everyone, every day.
  2. Each gives you one task: draw, fill, find, count, or stop. Respond by feel, then lock it in.
  3. Score out of 500, read your verdict, then challenge a friend. Come back tomorrow for a fresh five.
≈60 SECONDS · 5 ROUNDS · NO ACCOUNT · CHALLENGE A FRIEND
01 The Instrument Bank 100 IN BANK · 5 A DAY
► Tap any instrument to practice it free: unlimited tries, never counts toward your daily.
How-to demos
▶ PRACTICE
MODULE 01
Angle
Draw an exact angle by feel. Drag out from the pivot and trust the gut.
125°
▶ PRACTICE
MODULE 02
Fill
Fill the vessel to an exact percentage. Stop when it feels right.
64%
▶ PRACTICE
MODULE 03
Midpoint
Tap the true middle of the line. No marks, no guides. Just balance.
Δ 7px
▶ PRACTICE
MODULE 04
Flash Count
Dots appear for one second. Count them before they vanish.
FLASH 1.0s
▶ PRACTICE
MODULE 05
Blind Timer
Stop the hidden clock on the target time. No display. Count it down inside.
TGT 3.20s
▶ PRACTICE
MODULE 06
Balance
Slide the fulcrum to the balance point of two unequal weights. The heavier block sits closer.
PIVOT 38%
▶ PRACTICE
MODULE 07
Span
Draw a line an exact multiple of the reference. Match the ratio by eye.
× 3.0
▶ PRACTICE
MODULE 08
Bisect
Split the angle exactly in half. No protractor. Lay the divider on the bisector.
SPLIT 1/2
▶ PRACTICE
MODULE 09
Area
Size the circle to match the square's area. Equal area, not equal width.
EQUAL AREA
▶ PRACTICE
MODULE 10
Reflex
Tap the instant the sweep crosses the mark. One pass. Feel the timing.
TAP ON MARK
▶ PRACTICE
MODULE 11
Perpendicular
Drop a line at a clean right angle to a tilted reference. Trust the corner.
RIGHT ANGLE
▶ PRACTICE
MODULE 12
Shade
See a gray for a beat, then rebuild it from memory. Pure tone recall.
MATCH THE TONE
▶ PRACTICE
MODULE 13
Tempo
Four pulses set the beat, then you keep it. Hold the tempo by feel.
KEEP THE BEAT
▶ PRACTICE
MODULE 14
Ratio
Cut a bar to a named fraction: a third, two-fifths, the golden cut.
1/3
▶ PRACTICE
MODULE 15
Flick
Flick the puck and let friction carry it to rest inside the zone.
FLICK TO ZONE
▶ PRACTICE
MODULE 16
Rotate
Twist the dial to an exact bearing. No degree marks, just the gut.
240°
▶ PRACTICE
MODULE 17
Hold
Press and hold for an exact span of seconds. The clock goes dark. Feel it.
··· 3.4s
▶ PRACTICE
MODULE 18
Recall
A line flashes, then vanishes. Redraw its exact length from memory.
FROM MEMORY
▶ PRACTICE
MODULE 19
Spinner
Numbers race past. Tap to stop the reel on the target. Anticipate, don't react.
27 STOP ON 27
▶ PRACTICE
MODULE 20
Aim
Set the launch angle and fire. Fixed power. Find the arc that drops it on target.
FIND THE ARC
▶ PRACTICE
MODULE 21
Mirror
Reflect a dot across a tilted axis. Place its mirror image by eye.
REFLECT IT
▶ PRACTICE
MODULE 22
Interval
Two flashes mark out a gap. Reproduce that exact gap with two taps.
TAP THE GAP
▶ PRACTICE
MODULE 23
Estimate
A swarm of dots, too many to count. Estimate the number by feel.
HOW MANY?
▶ PRACTICE
MODULE 24
Speed
A dot sets the pace. Slide until your dot moves at exactly the same speed.
MATCH THE PACE
▶ PRACTICE
MODULE 25
Mean
Two numbers, no number line. Find the value exactly halfway between them.
40 190 ? HALFWAY
▶ PRACTICE
MODULE 26
Parallel
Match a reference line's exact lean. Draw a parallel by eye, no protractor.
SAME LEAN
▶ PRACTICE
MODULE 27
Countdown
A clock falls to zero, then goes dark partway. Tap the instant it hits 0.
0.0 TAP AT ZERO
▶ PRACTICE
MODULE 28
Centroid
Find a shape's balance point, where it would sit level on a pin.
BALANCE POINT
▶ PRACTICE
MODULE 29
Bigger
How many times bigger is one area than another? Judge area, not width.
HOW MANY ×?
▶ PRACTICE
MODULE 30
Percent
Two numbers, no scratch paper. What percent is the first of the second?
35 / 140 ?% ESTIMATE %
▶ PRACTICE
MODULE 31
Trisect
Split a line into three equal parts with two dividers. Thirds by eye.
EQUAL THIRDS
▶ PRACTICE
MODULE 32
Gauge
Read an unlabeled gauge by eye. Where is the needle pointing, 0 to 100?
READ IT
▶ PRACTICE
MODULE 33
Product
Estimate the product of two numbers. Fast and by feel, no scratch paper.
23 × 34 ≈ ? ESTIMATE
▶ PRACTICE
MODULE 34
Pendulum
A bob swings back and forth. Tap the instant it crosses the mark.
TAP ON MARK
▶ PRACTICE
MODULE 35
Level
Set a bar to true horizontal while a tilted frame fights your eye.
TRUE LEVEL
▶ PRACTICE
MODULE 36
Arc
Read how many degrees a drawn arc sweeps, by eye.
270°?
▶ PRACTICE
MODULE 37
Longer
Two lines. How many times longer is one than the other? Length only.
HOW MANY ×?
▶ PRACTICE
MODULE 38
Lever
Place a weight to balance the lever by torque. Heavier sits closer in.
BALANCE IT
▶ PRACTICE
MODULE 39
Logscale
Place a number on a logarithmic scale from 1 to 1000. Decades, not tenths.
1 · 10 · 100 · 1000
▶ PRACTICE
MODULE 40
Meter
Tap five evenly spaced beats at any tempo. Scored purely on steadiness.
EVEN BEATS
▶ PRACTICE
MODULE 41
Duration
A light glows for a few seconds. Estimate how long it stayed lit.
HOW LONG?
▶ PRACTICE
MODULE 42
Apex
A shot rises to its peak, then vanishes. Tap where it comes back down.
WHERE IT LANDS
▶ PRACTICE
MODULE 43
Divide
Estimate one number divided by another. Fast, no long division.
340 ÷ 8 ≈ ? ESTIMATE
▶ PRACTICE
MODULE 44
Density
Two equal patches. Add dots to the right until it looks as dense as the left.
MATCH DENSITY
▶ PRACTICE
MODULE 45
Scale
Resize a square to a target multiple of a reference's area. Area, not width.
2× THE AREA
▶ PRACTICE
MODULE 46
Nest
Size a ring to sit exactly between two others. Dead center of the gap.
SPLIT THE GAP
▶ PRACTICE
MODULE 47
React
Wait for the panel to turn red, then tap as fast as you can. Pure reflex.
TAP! ON RED
▶ PRACTICE
MODULE 48
Corners
A many-sided shape flashes for a second. Count its corners from memory.
HOW MANY?
▶ PRACTICE
MODULE 49
Gears
The big gear turns a known angle. Predict where the meshed small one ends up.
MESHED GEARS
▶ PRACTICE
MODULE 50
Fraction
Estimate a named fraction of a whole number: three fifths of 240, by feel.
⅗ of 240 ≈ ? ESTIMATE
▶ PRACTICE
MODULE 51
Hue
Memorize a colour, then recreate its hue from memory on a spectrum.
colour ≈ ? MEMORY
▶ PRACTICE
MODULE 52
Sum
Add three numbers in your head and slide to the total.
34 + 51 + 18 ≈ ? ADD
▶ PRACTICE
MODULE 53
Pour
Split liquid between two tanks to hit a target ratio.
2 : 1 █░ RATIO
▶ PRACTICE
MODULE 54
Slice
Grow a pie wedge to a target central angle, by feel.
110° ◔ WEDGE
▶ PRACTICE
MODULE 55
Clock
Set an analog clock to a target time by dragging the hour and minute hands.
set the time 3:40 CLOCK
▶ PRACTICE
MODULE 56
Vernier
Slide two line segments into one perfectly straight line.
│ │ align ACUITY
▶ PRACTICE
MODULE 57
Tally
Estimate what percent of a dot field is red.
●●○ % red ESTIMATE
▶ PRACTICE
MODULE 58
Root
Estimate a square root and slide to your answer.
√50 ≈ ? ROOT
▶ PRACTICE
MODULE 59
Aspect
Resize a rectangle to a target width-to-height ratio.
16 : 9 ▭ SHAPE
▶ PRACTICE
MODULE 60
Tangent
Rotate a ray until it just grazes the edge of a circle.
◯ graze TANGENT
▶ PRACTICE
MODULE 61
Difference
Subtract two numbers in your head and slide to the result.
82 - 19 ≈ ? SUBTRACT
▶ PRACTICE
MODULE 62
Blend
Slide a swatch to the gray exactly halfway between two others.
░▒▓ mid BLEND
▶ PRACTICE
MODULE 63
Mix
Combine two paints to a target ratio, like 1 to 3.
1 : 3 █░ RATIO
▶ PRACTICE
MODULE 64
Center
Drop a dot in the visual centre of an off-square frame, by eye.
□ · CENTRE
▶ PRACTICE
MODULE 65
Grade
Set a ramp to a target road grade, rise over run.
15% ◢ GRADE
▶ PRACTICE
MODULE 66
Odds
Turn odds like 1 in 8 into the matching percentage.
1 in 8 ≈ ?% CHANCE
▶ PRACTICE
MODULE 67
Remainder
Split items into rows and find how many are left over.
37 / 8 rem ? MODULO
▶ PRACTICE
MODULE 68
Symmetry
Drop a line where a lopsided shape balances left and right.
▘▛▜ axis BALANCE
▶ PRACTICE
MODULE 69
Stack
Make one bar a target fraction of a reference bar's height.
B = ⅔ A ratio STACK
▶ PRACTICE
MODULE 70
Tilt
A line flashes; reproduce its slant from memory.
╱ slant MEMORY
▶ PRACTICE
MODULE 71
Discount
Take the percent off a price; land the sale total.
25% off 80 = 60 SALE PRICE
▶ PRACTICE
MODULE 72
Digits
Add up the individual digits of a number.
4 8 2 7 = 21 DIGIT SUM
▶ PRACTICE
MODULE 73
Sequence
Spot the pattern and give the next number.
2 5 8 ? NEXT
▶ PRACTICE
MODULE 74
Double
One cell keeps doubling; estimate the total.
1·2·4·8·16 × 2 … DOUBLING
▶ PRACTICE
MODULE 75
Brightest
Pick the lightest of near-equal grays.
LIGHTEST
▶ PRACTICE
MODULE 76
Blur
Match a target's focus by feel.
FOCUS
▶ PRACTICE
MODULE 77
Odd One
Find the one tile that's a different color.
ODD ONE
▶ PRACTICE
MODULE 78
Wedge
Read what percent a pie slice fills.
PERCENT
▶ PRACTICE
MODULE 79
Overlap
Estimate how much two circles overlap.
OVERLAP
▶ PRACTICE
MODULE 80
Triangle
Estimate a triangle's share of its frame.
AREA %
▶ PRACTICE
MODULE 81
Slingshot
Judge angle and power to land the shot on target.
LAUNCH
▶ PRACTICE
MODULE 82
Bank
Bank the ball off the cushion into the pocket.
BANK SHOT
▶ PRACTICE
MODULE 83
Collide
Cut the object ball into the corner pocket.
CUT
▶ PRACTICE
MODULE 84
Bounce
Predict where the ball lands after the bounce.
BOUNCE
▶ PRACTICE
MODULE 85
Drop
Catch a ball that keeps the moving crane's speed.
MOMENTUM
▶ PRACTICE
MODULE 86
Wind
Aim against the crosswind to hit the target.
WIND AIM
▶ PRACTICE
MODULE 87
Spring
Compress a spring to launch the ball to the mark.
SPRING
▶ PRACTICE
MODULE 88
Ramp
Angle the ramp so the ball rolls off on target.
RAMP
▶ PRACTICE
MODULE 89
Putt
Judge the putt so the ball stops dead on the mark.
ROLL
▶ PRACTICE
MODULE 90
Orbit
Release an orbiting ball so its line hits the target.
TANGENT
▶ PRACTICE
MODULE 91
Converge
Tap where two converging rails would meet.
VANISH
▶ PRACTICE
MODULE 92
Protractor
Read the angle between two arms by eye.
ANGLE
▶ PRACTICE
MODULE 93
Vivid
Match a swatch's colour saturation.
VIVID
▶ PRACTICE
MODULE 94
Contrast
Match the lightness gap between two chips.
CONTRAST
▶ PRACTICE
MODULE 95
Growth
Read the percent increase from one number to another.
+ %
▶ PRACTICE
MODULE 96
Recipe
Scale a recipe up in proportion.
3 : 12 × ?
▶ PRACTICE
MODULE 97
Scale Bar
Read a length off a map scale.
50 m ? m
▶ PRACTICE
MODULE 98
Diagonal
Estimate the diagonal across a rectangle.
DIAGONAL
▶ PRACTICE
MODULE 99
Median
Estimate the middle of five numbers.
MEDIAN
▶ PRACTICE
MODULE 100
Perimeter
Estimate the distance around a rectangle.
around PERIMETER
02 Scoring & Verdict SCALE 0-500

One run. Five readings.

Each round is scored 0-100 on how close your instinct lands to the day's hidden target. The five readings sum into a single calibration score. The needle settles, and the panel hands down a verdict.

412/ 500
82% CALIBRATED · VERDICT: SURGEON
ANGLE
94
FILL
88
MIDPOINT
79
FLASH
71
TIMER
80
TOTAL
412

The verdict ladder

Where the needle lands names your gut. Climb from RECALIBRATE to MACHINE. Most careful humans settle in the middle, with room to sharpen.

95-100% MACHINE
85-94% SURGEON
70-84% CALIBRATED
55-69% HUMAN
40-54% FOGGY
< 40% RECALIBRATE
03 Play With Friends DUEL · ROOM · PERCENTILE
04 One Day. One Check. GLOBAL SYNC
SEEDED FROM THE DATE · WORDLE CONVENTION

Everyone on Earth gets the same five challenges.

The day's targets are seeded from the date, identical for every player, everywhere. No edge, no do-overs. You get one run. Come back tomorrow for a fresh five.

NEXT CHECK IN
07:42:15
RESETS AT LOCAL MIDNIGHT
05 FAQ QUICK ANSWERS

Is GUT CHECK free?

Yes, completely free. No account, no subscription, and no in-app purchases. It runs entirely in your browser.

How is GUT CHECK different from Wordle?

Wordle tests vocabulary; GUT CHECK tests perception, your ability to estimate angles, distances, timing, and quantities with no reference. The format echoes Wordle: one attempt a day, the same puzzle for everyone. Now you can also challenge friends head to head.

Is there a Wordle for perception or reaction time?

Yes. GUT CHECK is a free daily perception and instinct game in the Wordle format: instead of guessing a word, you calibrate your gut against five hidden targets, such as angles, timing, and quantities, every day.

Is GUT CHECK a brain game?

Yes, but not a trivia or memory game. It is an estimation and instinct game: there is nothing to memorize or look up, you are testing your raw feel for angles, proportions, timing, and quantity.

How many instruments are in GUT CHECK?

There is a bank of 100 instruments. Each day, five are drawn, seeded from the date, so every player on Earth gets the same five. Examples include drawing an angle by feel, filling a vessel to a percentage, finding a line's midpoint, counting dots from a one-second flash, and stopping a hidden timer.

Does GUT CHECK work on mobile?

Yes. It is a mobile-first web app with touch input and installs as an offline PWA on iOS and Android. There is nothing to download.

How is the score calculated?

Each round scores 0 to 100 based on how close you land to the hidden target. Five rounds sum to a score out of 500. Around 70 to 84 percent earns CALIBRATED, 85 percent and up earns SURGEON, and 95 percent and up earns MACHINE.

Do I need an account to play?

No. There is no sign-up and no tracking. Your streak and stats are stored only on your own device.

CHECK #142 · IS LIVE

CALIBRATE YOUR
INSTINCTS.

≈60 seconds · 5 rounds · no account · no tracking

PLAY TODAY'S CHECK