Can You Spot the AI's Mistake? A Free 5-Minute Coding Game

By Pooja Goenka ยท 2026-10-04

Here is a short answer an AI wrote about JSON. Four lines are true and one is not. Read it once and decide which one before you scroll.

What are the basic rules of JSON?

  1. JSON is a plain-text format for structured data, and most languages can read and write it.
  2. Object keys must be strings in double quotes, so {name: 1} is not valid JSON.
  3. Values can be strings, numbers, true, false, null, arrays or objects.
  4. You can add a comment on its own line with //, and parsers skip it like whitespace.
  5. A trailing comma after the last item, as in [1, 2,], is not allowed.

It is line 4. Standard JSON has no comments at all. RFC 8259, the JSON standard, defines none, and a strict parser such as JavaScript's JSON.parse throws an error on that line. Some tools accept comments as an extension, which is exactly why the claim sounds plausible.

If you got it, you also had to resist line 5, which sounds like a fussy rule someone made up and is in fact correct. That is the whole game.

Why practise this at all

More and more of the code and explanations engineers work with now start as an AI draft. The skill that matters is no longer only producing an answer. It is reading a fluent, well-structured answer and noticing the one sentence that would break production. I wrote about why confident wrong answers are the most useful thing to practise on separately.

That skill is hard to drill with normal quizzes, because a quiz question tells you something is being tested. Here, the wrong line looks exactly like the right ones.

How Spot Aria's Mistake works

Spot Aria's Mistake is a free game on LogicWiz Arena. Aria, an AI, answers a question in five lines, and one line is wrong.

  • Five rounds in a game, about five minutes in all.
  • Pick a track: AI, Python, Frontend, Backend and APIs, SQL and databases, Data engineering, Cloud and DevOps, or DSA and OOP.
  • Lines appear at reading pace. The clock starts after the last line, and you have 20 seconds to tap the wrong one.
  • Then say why it is wrong. You get three explanations to choose from, and 15 seconds.
  • Scoring: 100 points for the right line, 50 for the right reason, and a speed bonus of up to 100 if you are quick.

Every player gets a certificate with a badge, so a first try is worth finishing.

The October Open

The current event, the October Open, is open to everyone until 19 October. The top 10 on the scoreboard get free LogicWiz goodies, and winners are announced on 20 October. It is one entry per person, so you sign in with Google before the first round. That takes one tap.

If you would rather warm up first, the event page has a free practice round that needs no sign-in at all.

Tips from the sample round

  • Read for the claim, not the tone. Every line is written with the same confidence. The wrong one is not flagged by hedging words.
  • Distrust the rule that sounds convenient. Line 4 was wrong because it describes what we would like JSON to allow.
  • Do not overcorrect. Line 5 sounds pedantic and is true. Calling something wrong when it is right costs you the round.
  • Say the reason to yourself before you see the options. The wrong reasons are written to be tempting.

Common questions

Is Spot Aria's Mistake free?

Yes. The game is free to play, and the October Open is free to enter.

Do I need an account?

You can try a practice round on the event page without one. To play the scored event you sign in with Google, because each person gets one entry.

Which topics are covered?

Eight tracks: AI, Python, Frontend, Backend and APIs, SQL and databases, Data engineering, Cloud and DevOps, and DSA and OOP. You pick one before you start.

How long does a game take?

About five minutes for five rounds.

What do I get for playing?

Every player gets a certificate with a badge. In the October Open, the top 10 on the scoreboard get free LogicWiz goodies.