FAULTLIGHT
FAULTLIGHT is a daily 3×3 lamp logic puzzle where you restore nine lamps from counts shown by sensors and identify the single sensor giving a wrong count; it resets daily at 00:00 UTC.
Play FAULTLIGHTA fresh puzzle is waiting for you.
FAULTLIGHT presents a 3×3 grid of lamps. Each lamp can be on or off. Small numbers next to groups indicate how many lamps are lit in that group, and exactly one of those numbers is incorrect due to a faulty sensor.
Each daily puzzle has exactly one verified solution. The site offers one daily puzzle plus a practice mode. The publisher checked all 512 possible lamp configurations to ensure uniqueness of the solution.
Play requires no account, the game is free and runs in English and Japanese. The site states it is ad-free, offers hints, a spoiler-free result share option, and an option to view a revealed solution (which will be recorded and not counted as a self-solved game).
New daily puzzles appear worldwide at 00:00 UTC (noted as Japan time 09:00). The game was created as an original puzzle with AI assistance.
How to play FAULTLIGHT
- Open today’s puzzle and inspect the 3×3 lamp grid and the small numbers that indicate counts of lit lamps in nearby locations.
- Tap a lamp to cycle its state between unknown, lit, and unlit; fixed lamps cannot be changed.
- When you think the lamp arrangement is correct, choose one sensor as the faulty one that shows the wrong count.
- Submit your selected lamp configuration and faulty sensor to check the answer, use hints if needed, or view the solution (viewing is recorded).
Tips for FAULTLIGHT
- Trust the numbers except for a single sensor; assume each number is correct until you find a contradiction that requires the faulty one.
- Use the fixed lamps and given counts to deduce forced lights or darks first, then test which single sensor being wrong resolves any remaining conflicts.
- Work systematically row by row or by overlapping count regions to narrow candidates rather than flipping lamps at random.
- If stuck, use practice puzzles to build familiarity before attempting the daily puzzle, and use the hint feature sparingly to preserve challenge.
FAULTLIGHT FAQ
What is FAULTLIGHT?
FAULTLIGHT is a daily logic puzzle played on a 3×3 lamp grid where you must restore the lamp states and identify the single sensor showing an incorrect lamp count; the puzzle supplies counts for small regions and exactly one count is wrong, and each daily puzzle has one verified solution.
Is FAULTLIGHT free to play?
Yes, FAULTLIGHT is free to play with no account required and the site states it is ad-free; it also offers practice puzzles and optional hints.
When does the new FAULTLIGHT puzzle appear?
A new FAULTLIGHT daily puzzle appears each day at 00:00 UTC, which the site notes corresponds to 09:00 in Japan, and everyone worldwide gets the same puzzle on that schedule.
Can I play practice puzzles in FAULTLIGHT?
Yes, the site provides a practice mode separate from the daily puzzle so you can play additional problems to train before or after attempting the daily challenge.
How many solutions does each FAULTLIGHT puzzle have?
Each FAULTLIGHT daily puzzle is verified to have exactly one solution; the creator examined all 512 lamp configurations to confirm uniqueness for each puzzle.
Does FAULTLIGHT work on mobile devices?
Yes, FAULTLIGHT supports tapping controls and the interface describes tapping a lamp to cycle its state, indicating it is designed to work on touch devices as well as desktop browsers.
What does selecting a sensor mean in FAULTLIGHT?
Selecting a sensor designates the one small-number indicator you believe is incorrect; you first set the lamp states and then choose which sensor is faulty before submitting to check your solution.
Can I share FAULTLIGHT results without spoiling the answer?
Yes, the game provides a spoiler-free share option and a result card you can copy to send to friends while keeping the actual solution hidden.
Or play directly at faultlight-daily.yoshitaka20050525.chatgpt.site
