FAQ
Everything you need to know about COSTLY.
What is COSTLY?
A daily guessing game about real-world costs: how much is an Airbus, a stadium or a year of running the ISS? You guess, see the reference value, and learn the orders of magnitude the world runs on.
How many questions are there per day?
The Daily Challenge has 5 questions from 5 different categories, ordered from easy to hard. New questions arrive at midnight (Central European Time) – the same ones for every player. Missed a day? Every past Daily is in the archive.
How are points calculated?
What counts is the factor you’re off by, not how many euros. Exact is 100 points, 2× off earns 85, 10× off still 50, and from 100× off you get nothing. Too high and too low count the same. See scoring →
Can I catch up on days I missed?
Yes – the archive has every past Daily Challenge. Archive rounds count toward your stats, but don’t extend your daily streak.
How does the streak work?
Your streak counts how many days in a row you finished the Daily Challenge on the day itself. Skip a day and it starts over.
Where do the prices come from?
Each of the 219 questions has a source, a reference year, a cost type (e.g. list price or construction cost) and a short explanation. Prices from around the world are shown in euros, converted at the annual average rate of their year. The values are rounded orders of magnitude – prices vary by country, spec and negotiation.
Where are the photos from?
Every question shows a photo of the object so you can picture it even if you've never heard of it. The photos come from Wikimedia Commons under free licences (Creative Commons or public domain). The author and licence are under each photo, and the credit links to the original file.
Do I need an account? What happens to my data?
No account needed. Progress, records and settings are stored only locally in your browser. If the player counter is active, only your daily score is counted anonymously after the Daily – no name, no identifier. You can reset everything in the settings.
Is there a dark mode?
Yes. Tap the slider icon at the top right to open the settings and choose Light, Dark or System. You can also reduce animations there.