How to play
Choose the passage written by AI. The other is an excerpt from a public-domain novel in its original language. Five pairs make a round. Each choice reveals the novelist and work immediately.
Challenge a friend
The daily five change by UTC date. The share button creates a link with the same language, passages and A/B positions, without sending answers. “New five” creates another set. Each round draws from five different works. The score is the number of correct choices; speed and confidence do not affect it.
Original languages, separate sets
Korean uses fiction originally written in Korean. English uses fiction originally written in English. No translated passages are used. Each language contains 24 classic excerpts and 24 AI-written counterparts.
How the AI passages were made
An OpenAI assistant wrote them for this game, referring to the length and period atmosphere of the paired excerpt while inventing a separate scene. We do not claim a particular model version or a representative random sample of AI writing. Human-written passages are never labelled AI.
Your score is not an AI detector
This is a game comparing short, selected excerpts. Style, older spelling, recognition of a novel and chance can influence choices. Smooth prose does not prove AI authorship, and specific details do not prove human authorship. Your score cannot establish real-world authorship, misconduct or intelligence. Do not use this game to accuse or authenticate anyone.
Keyboard and progress
Press 1 or 2 to choose, or use Tab, Enter and Space. There is no timer. Progress stays in this browser so a refresh can resume it. Answers and scores are not uploaded. The app can be installed; previously visited pages may work offline, but unvisited resources and external source links need a connection.