The rarity engine
How scoring works
Lower is better. Your answer scores the share of all valid responses that went to answers at least as popular as yours. Only answers in the thin tail are rare — if dozens of answers are about equally common, none of them is.
e = estimated share of answer = w / Σw
p = (n + 100·e) / (N + 100)
score = round(100 × Σ p_j for every answer j with p_j ≤ p)
n = players who gave this answer · N = all valid answers to the question · w = cold-start prominence weight
Cold start, honestly labelled
Before real players answer a question, every accepted answer carries an estimated weight. For countries and capitals it is √(population in millions), tripled for globally famous places; for physical features it is the square of a 0–10 familiarity rating. These estimates act as 100 “imaginary” responses, so real answers gradually take over. Until a question has 30 real valid responses, its scores are labelled estimated.
Frozen daily distributions
When a daily challenge begins, the score of every accepted answer is frozen. Everyone answering that day is judged against the same table. New answers update the statistics only for future challenges and practice.
Fair answer matching
Answers are matched after removing accents, punctuation and generic words (“River”, “Lake”, “Mount”). Aliases and spellings map to one canonical place, so “Czech Republic” scores exactly like “Czechia”. Small typos on long names are forgiven. Wrong answers are never locked — you can try again, or give up for 100 points.
One official attempt
Your first run of each daily challenge is your official result. Locked answers cannot be changed. You can review a finished game at any time, and practise freely on older questions without touching your streak.
The landscape
Terrain height follows your average points per question on a fixed scale: 0 average is sea level, 100 is the highest summit. The same total always draws the same landscape.
The atlas
0 questions across 20 categories. Country questions are generated from a structured dataset (ISO 3166 country set with borders, regions and landlocked status; World Bank 2022 population) so their answer lists are computed, not guessed. Physical-geography lists cite their references on each question. 0 questions with too few valid answers are flagged for review and kept out of daily play.