Trivia Arena

One question at a time, four answers, and an explanation for every one. 1549 questions, six modes, and a source under every answer. Nothing to install and no sign-up.

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How to play

A question appears with four answers. Choose one — by tapping it, or with the number keys 1 to 4.

Choosing commits your answer. The options freeze, the right answer is marked, and an explanation appears. You cannot change your mind — if you could, the score at the end would mean nothing. Press Enter for the next question.

A streak is a run of right answers in a row. Your best is kept for each mode separately, on this device.

Where the questions come from

Every question here is built from a fact table written for this site, and every one shows its source under the explanation. Nothing is scraped or copied from a commercial trivia database. The pack currently draws on:

general natural-history reference: the everyday animal groups
general human-anatomy reference
reference geography: sovereign states and their capitals
the periodic table of the elements
common chemical formulas
the standard Roman numeral system
elementary geometry
general astronomy reference: the solar system
the International System of Units

The wrong answers are provably wrong. Each question knows which other facts would also answer it correctly, and bars them from being offered. That check runs when the pack is built, so “which of these is a noble gas?” can never quietly contain two noble gases.

Where a fact is disputed, we leave it out. Bolivia and South Africa are never the subject of a capital question, because they do not have one capital between them to ask about. Polonium is never the answer to a question about which class it belongs to, because chemists do not agree. A trivia game is allowed to be incomplete; it is not allowed to mark a correct answer wrong.

Modes

Quick 10: Ten questions, no clock, every category. The short version — start here and see what the bank is like.
Classic 25: Twenty-five questions with twenty seconds on each. Long enough that concentration matters and quick enough that hesitating costs you — a different problem from Quick 10, not a longer one.
Endless: No end and no clock. What is kept is your LONGEST RUN of right answers, so a wrong one costs you the run you were on rather than the game — the opposite of Sudden Death.
Category Run: Fifteen questions from a single subject, with its own best kept separately. Being good at geography tells you nothing about your chemistry, so the two are not added together.
Daily 10: The same ten questions for everybody, seeded by today's UTC date. No best is kept — a different ten each day cannot be compared — but the result and the streak are.
Sudden Death: It ends the first time you are wrong. You still see why before it does. What is kept is how far you got.

Subjects

Science and Geography and Nature and Maths, with more to come. Category Run plays fifteen questions from one subject and keeps a best for each separately — being good at geography says nothing about your chemistry.

Privacy and local play

Everything runs in your browser. Your scores, your streaks and the questions you have already seen are kept in this browser's local storage and are never sent anywhere — there is no account, no server and no leaderboard. Clearing this game's data from the panel above removes all of it and touches nothing else on Zerdly.

Frequently asked questions

Why can I not change my answer?: Because the explanation appears the moment you choose. If you could re-pick after seeing which answer was right, the score at the end would mean nothing — you would simply be reading the answers in a slower way. Choosing is committing, and the game tells you that before you start.
Where do the questions come from?: They are built here from fact tables written for this site — the periodic table and reference geography so far — and nothing is copied from a commercial trivia database. Every question shows its source under the explanation. There are 1549 questions in the pack at the moment, in 25 different question shapes.
How do you know the wrong answers are actually wrong?: Because it is checked when the pack is built rather than hoped for. Each question knows which other facts would also be a correct answer to it, and those are barred from ever being offered. Asked which of four is a noble gas, none of the other three is one — that is a property of the pack, not of the author's memory.
A question left out a country I expected. Why?: Where a fact is genuinely disputed we leave it out rather than pick a side. Bolivia has a constitutional capital and a seat of government in different cities, South Africa has three capitals, and polonium is drawn as a metalloid on some periodic tables and a metal on others — so none of those is ever the answer to a question about it. The countries and elements are still there for the questions that do have one settled answer.
What is the difference between Endless and Sudden Death?: They are opposites that happen to share a length. Endless never stops and keeps your longest run of right answers, so a mistake costs you the run you were on. Sudden Death ends the first time you are wrong — though you still see the explanation for the question that ended it.
Why is there no leaderboard?: Because there is no server and no account, so there is nobody to compare you with. Your scores are kept in this browser and nowhere else. We would rather show you your own best than invent a rank.
Why does the Daily not keep a best score?: It is a different ten questions every day, so a best would be comparing today's ten with a different ten from a fortnight ago. It keeps your result for each day and how many days in a row you have played, which are the only honest things to keep.