GENERAL KNOWLEDGE — SOURCES AND CRITERIA Map: Natural Earth, 1:50m country boundaries (public domain). https://www.naturalearthdata.com/ https://github.com/nvkelso/natural-earth-vector Flags: flag-icons 7.5.0 (MIT license, available in /flags/LICENSE.txt). https://github.com/lipis/flag-icons 30 largest economies: projected nominal GDP for 2026 in current U.S. dollars, IMF World Economic Outlook, April 2026 edition. Ranking snapshot: September 23, 2026. https://data.imf.org/Datasets/WEO https://www.imf.org/external/datamapper/NGDPD@WEO Country set: 193 United Nations members plus the observer states of Palestine and Vatican City. Dependent territories appear on the map but are not drawn as questions. The opening economic stage also includes Taiwan because the IMF ranking treats it as a separate economy. Stage order: Top Economies, South America, Europe, Middle East, East Asia, Southern Africa, Northern Africa, North and Central America, Oceania. The two Asian stage names are simplified. Middle East includes Western and Central Asia plus Iran. East Asia includes South, Southeast, and East Asia. The split uses Natural Earth subregions. Africa is divided by the Democratic Republic of the Congo. The DRC and countries whose Natural Earth label point is at or south of the DRC label point are in Southern Africa. Countries whose label point is north of it are in Northern Africa. Southern Africa comes first. Other regional conventions follow Natural Earth: Russia is in Europe; Turkey, Cyprus, and the Caucasus are in Asia; North and Central America includes Canada, the United States, Mexico, Central America, and the Caribbean. Somaliland and Northern Cyprus are grouped with Somalia and Cyprus for answers. Simplified outlines are intended for educational use. Very small countries have a selection dot. Use zoom and drag to inspect the map. The outline preview uses Natural Earth 1:10m boundaries for small countries and appears for every country. Rules: five different countries per stage and twelve seconds per question. Score = correct answer × seconds remaining × stage number. Scores are truncated to one decimal place. A wrong answer or timeout earns zero. The minimum score to advance is 30 × stage number, half of the theoretical maximum. Failing a stage ends the game and restarts the next attempt from stage one with zero points. Capitals: Natural Earth 1:10m populated places. Primary administrative-capital points are used, with current administrative choices for South Africa (Pretoria), Bolivia (Sucre), Côte d'Ivoire (Yamoussoukro), Sri Lanka (Sri Jayawardenepura Kotte), Tanzania (Dodoma), and Burundi (Gitega). Juba, Yaren, and Ramallah complete countries without a primary capital marker in the dataset. https://www.naturalearthdata.com/downloads/10m-cultural-vectors/10m-populated-places/ https://github.com/nvkelso/natural-earth-vector Locate the Capital uses the same stages with fifteen seconds per question. Each click starts at 10 distance points and loses 1 point per 200 km from the capital, reaching zero at 2,000 km. Landing inside the correct country adds a 3-point country bonus. The combined score is multiplied by the stage number and truncated to one decimal place. The minimum to advance is 32.5 × stage number, half of the 65 × stage number maximum. A timeout earns zero, and failing a stage restarts the game from stage one. Guess the Country facts: country area, currencies, languages, and land borders are prepared from the mledoze/countries dataset. Population values use the latest available World Bank SP.POP.TOTL observation. GDP uses the latest available World Bank NY.GDP.MKTP.CD observation for each country, with ranks calculated across the game's country set. HDI values and official ranks are from UNDP's 2025 Human Development Report dataset and refer to 2023. The leading merchandise export uses the highest-value HS4 product in the OEC BACI 2024 dataset. Capitals use the Natural Earth dataset described above. Current heads of government are prepared from non-deprecated, non-ended Wikidata P6 statements. Flag-color clues are measured from the displayed flag artwork and include only exact colors covering more than 5% of its pixels. https://github.com/mledoze/countries https://data.worldbank.org/indicator/SP.POP.TOTL https://data.worldbank.org/indicator/NY.GDP.MKTP.CD Zoom City uses the 500 largest supported cities by 2025 population from the United Nations World Urbanization Prospects 2025 bulk city dataset. Coordinates are UN population-weighted city centroids. Difficulty is calculated from percentile ranks using 65% latest country GDP and 35% city population, then split into three equal-sized bands. https://population.un.org/wup/ https://population.un.org/wup/assets/Download/Cities/WUP2025-DB-DEGURBA-Cities-Population-Surface-Data.csv.gz https://hdr.undp.org/data-center/documentation-and-downloads https://oec.world/ https://www.wikidata.org/wiki/Property:P6 Guess the Country uses five questions per stage and the same geographic stage pools as the other games. Each question starts with one revealed clue and ten visible country choices, all drawn from the current stage's theme: the 30 largest economies in stage one and only countries from the named region afterward. Correct answers are worth 5, 4, 3, 2, or 1 point according to the number of revealed cards, multiplied by the stage number. The optional helper grays out five wrong choices and reduces that question's answer value by one point. The available fact clues are selected randomly without guaranteed or prioritized categories. The complete flag is always card five. A validated partial-flag clue has a 35% chance of appearing only on card four, never contains the flag's center point, and shows no more than two significant colors when the full flag is tricolored. When a two-color flag has similarly sized color areas, its crop is deliberately offset so one color occupies between 65% and 85% of the partial image instead of reproducing the original balance. More than one border clue may appear when a country has multiple land neighbors, but each such card uses a different neighboring country. The minimum score to advance is half of the 25 × stage number maximum. A wrong answer earns zero, and failing a stage restarts the journey. Current-leader corrections can be maintained in country-leader-overrides.json and are merged over Wikidata whenever the Guess the Country data generator runs. Guess the Country inactivity timer: seven seconds without an action reveal the next card. Seven seconds after the fifth card end the current question with no answer and no points. Rank the Countries uses the same geographic stages and keeps the same ten countries for three randomly selected ranking themes. The built-in country facts provide population, area, nominal GDP, HDI, population density, GDP per capita, and number of land borders. Life expectancy, urban-population share, internet-use share, and energy use per capita use the latest available observation for each country from the World Bank Indicators API. International tourism uses international travel receipts in current U.S. dollars for the common pre-pandemic reference year of 2019; receipts replace arrival counts because national arrival-counting practices are not sufficiently comparable for a ranking game. Median age, coastline length, highest-point elevation, and total carbon dioxide emissions use the final archived CIA World Factbook country profiles, distributed as public-domain structured data by factbook.json. The CO2 ranking divides those total emissions by the population value used elsewhere in the game and is displayed in metric tonnes per person. A theme is selected only when at least ten eligible countries remain in the current stage. https://datahelpdesk.worldbank.org/knowledgebase/articles/889392 https://data.worldbank.org/indicator/SP.DYN.LE00.IN https://data.worldbank.org/indicator/SP.URB.TOTL.IN.ZS https://data.worldbank.org/indicator/IT.NET.USER.ZS https://data.worldbank.org/indicator/ST.INT.TVLR.CD https://data.worldbank.org/indicator/EG.USE.PCAP.KG.OE https://github.com/factbook/factbook.json Forest cover is forest area as a percentage of land area from the latest available World Bank AG.LND.FRST.ZS observation. Mean elevation uses the CIA World Factbook structured profiles. UNESCO World Heritage counts use the official UNESCO DataHub list; transnational properties count once for each participating country, and countries with no listed property receive zero. Average annual temperature is the 1991–2020 country mean calculated from the annual Copernicus ERA5 country series processed by Our World in Data using World Bank administrative boundaries. https://data.worldbank.org/indicator/AG.LND.FRST.ZS https://data.unesco.org/explore/dataset/whc001/ https://ourworldindata.org/grapher/average-annual-surface-temperature Rank the Countries scoring is based on positional distance. Each country earns 10 points in an exact position, 8 points at distance one, 6 at distance two, 4 at distance three, 2 at distance four, and zero at distance five or greater. Countries tied on the underlying value may occupy any position in their tied range without penalty. Theme points are multiplied by the stage number. The stage target is 60% of the 300 × stage-number maximum. Guess the Year uses selected worldwide political-boundary snapshots from A. Ourednik's Historical Basemaps project, beginning in 1500. The source dataset is licensed under GPL-3.0 and explicitly describes itself as a work in progress. Its BORDERPRECISION field is preserved in the game: approximate borders are rendered softer and more dashed than boundaries described as legally determined. Historical boundaries—especially before the modern state system—may represent overlapping authority or approximate zones rather than surveyed lines. Each round reveals curated contextual clues only after the player's answer. https://github.com/aourednik/historical-basemaps https://github.com/aourednik/historical-basemaps/blob/master/LICENSE The expanded curated set also uses Cliopatria, a worldwide geospatial database of historical political entities maintained by the Seshat Global History Databank and released under CC BY 4.0. Cliopatria polygons are selected when their FromYear/ToYear interval contains the displayed year, sorted from larger to smaller entities so nested polities remain visible, simplified for browser delivery, and shown with moderate boundary confidence. These maps are interpretations of historical territorial control and may contain overlapping entities. Land for which a snapshot has no polity polygon is shown as a muted, borderless Natural Earth silhouette; this avoids presenting missing source coverage as ocean without inventing modern borders. https://github.com/Seshat-Global-History-Databank/cliopatria https://creativecommons.org/licenses/by/4.0/ Guess the Year is a five-stage regional journey: World, Europe, the Americas, Asia, and Africa. The world stage draws from 40 curated moments, while the regional stages add further snapshot years chosen for locally visible changes. The Asian view extends from Turkey through India and Southeast Asia to Japan, and includes Russian and Soviet territory. Turkey and Ottoman territory can appear in both Europe and Asia. An exact answer earns 5,000 points; answers within 2, 5, 10, 25, 50, or 100 years earn 4,500, 4,000, 3,250, 2,250, 1,250, or 500 points respectively. More distant answers earn zero. The displayed date is the source snapshot year, not a claim that every shown territorial change occurred on January 1 of that year. In regional stages, historical polygons are clipped to the modern geographic footprint of the countries assigned to that region. Land outside the selected region remains visible only as a single muted silhouette, with no internal borders or political colors. The mask is only a display boundary and does not represent historical borders. The Africa stage uses fifteen end-of-year snapshots from CShapes 2.0 covering 1886–2011. CShapes maps independent states, colonies, protectorates, mandates and occupied territories, and records whether borders were clearly defined. The stage therefore adds several dates not used by the worldwide collection, while rendering partly undefined borders with the game's lower-confidence treatment. CShapes is licensed CC BY-NC-SA 4.0. https://icr.ethz.ch/data/cshapes/ https://creativecommons.org/licenses/by-nc-sa/4.0/ Order the Historical Events uses a curated set of dated events from Africa, Asia, Europe, North America, Latin America, and the Caribbean. Event labels always identify the relevant country or region. Dates marked "c." are approximate historical estimates. Broad chronology was checked against the British Museum African Kingdoms timeline, the Metropolitan Museum of Art Heilbrunn Timeline, Columbia University's Asia for Educators timelines, the United Nations decolonization history, and the Library of Congress U.S. History Primary Source Timeline. https://www.britishmuseum.org/sites/default/files/2024-04/African_Kingdoms_Timeline.pdf https://www.metmuseum.org/toah/ https://afe.easia.columbia.edu/timelines/ https://www.un.org/en/global-issues/decolonization https://www.loc.gov/classroom-materials/united-states-history-primary-source-timeline/ Each round draws ten events with distinct chronological keys. The player has 120 seconds to arrange them from earliest to latest. Dates remain hidden until submission or timeout. The result awards one exact-position point per event and allows the player to compare their arrangement with the correct timeline. The Arcade collection uses the same Natural Earth-derived country outlines already credited above. Guess the Political Party is a logo-identification quiz. The parties, their countries, founding years, ideologies and names come from Wikidata (wikidata.org, CC0): active political parties that have a logo, ranked by number of Wikipedia articles, up to three per country (npm run prepare:political-parties). Besides this world list the player can choose Europe (up to five parties of each European country) or one country alone (Brazil, United States, Germany, France, Italy, Spain, United Kingdom, Portugal, India, Japan, Argentina, Canada: up to 32 parties, the best known first). In a one-country game only the name is asked. The country lists follow what Wikidata records as existing parties, minus a hand list of organisations that are not parties running in elections today; small or regional parties appear in them. The game asks only for the country and the name; the founding year and the ideology are shown after each answer exactly as Wikidata lists them and are not an assessment by General Knowledge. Political-party logos are used solely for identification. The local copies in public/party-logos come from Wikimedia Commons; the file page, licence and author of each logo are recorded in public/political-parties.json, and trademark rules still apply. Exceptions recorded in the same file: logos that Commons does not have are the non-free files of a Wikipedia (English, Arabic or Indonesian), marked "Fair use (non-free logo)" (African National Congress, La Libertad Avanza, FSLN, Nation's Future Party, All Progressives Congress, Peoples Democratic Party, PDI-P, Gerindra, Chama Cha Mapinduzi, Prosperity Party), and the PSDB logo with the toucan (not available on Commons) is the party's own logo as published by O Globo (oglobo.globo.com), kept in scripts/party-logos. Some logos are cropped while the player guesses, to hide the party name written on them; the whole logo (-full.png) is shown after the answer. Guess the Number uses five fixed official country facts. Each round lasts 60 seconds and awards up to 1,000 points according to proximity within the displayed estimate range. Values are rounded only for display when appropriate. Brazil total area (2024): IBGE, 8,509,379.576 km². https://www.ibge.gov.br/geociencias/organizacao-do-territorio/estrutura-territorial/15761-geografia-do-brasil.html Japan estimated population (October 1, 2024): Statistics Bureau of Japan, 123,802,000. https://www.stat.go.jp/english/data/jinsui/2024np/index.html Mount Everest official height: Nepal Tourism Board, 8,848.86 m. https://tourismnpl.gov.np/ Canada total area: Statistics Canada, 9,984,670 km². https://www150.statcan.gc.ca/n1/pub/11-402-x/2012000/chap/geo/geo-eng.htm Australia total area: Geoscience Australia, 7,688,287 km². https://www.ga.gov.au/scientific-topics/national-location-information/dimensions/australias-size-compared Guess the National Emblem shows national coats of arms and state emblems. Each country's image is chosen from Wikidata (property P94 "coat of arms image", or P158 "seal image" when no coat of arms is recorded), matched by ISO 3166-1 alpha-2 code (P297), with manual overrides listed in scripts/prepare-emblems.mjs. Files come from Wikimedia Commons and are stored locally as WebP images of at most 480 pixels in /emblems/. The author, licence and Commons page of every image are recorded in /emblems.json; most national arms are in the public domain as official state insignia, and the use of some emblems may be restricted by national law independently of copyright. Where an emblem spells out the country name, the question shows a copy with that text blurred (areas listed in scripts/emblem-masks.json); the unmodified original is shown after the answer. Countries without a suitable image are listed under "excluded" in the same file and are left out of the game. https://www.wikidata.org/wiki/Property:P94 https://commons.wikimedia.org/wiki/Category:Coats_of_arms_of_countries Locate the Landmark uses 150 human-made landmarks in three difficulty pools (Easy, Normal, Hard; the "stage" field in /landmarks.json); each stage draws five, never two from the same city. Each landmark is shown with a detailed original illustration made for General Knowledge (/landmarks/.svg, generated by scripts/landmark-drawings/build.py; the drawings contain no text). Coordinates, cities and one-line facts are stored in /landmarks.json; coordinates mark the landmark itself (for the Great Wall, the Mutianyu section near Beijing; for the moai, Ahu Tongariki on Rapa Nui). Scoring: accuracy (1 at the exact spot, 0 beyond 2,500 km) × seconds left (15 per landmark) × stage; 50% of the available points are needed to advance. What's Between Them? uses land borders computed from the Natural Earth country polygons already used for the map: two playable countries are neighbours when their outlines share boundary points (scripts/prepare-borders.mjs). French Guiana and the exclaves of Kaliningrad (Russia), Nakhchivan (Azerbaijan) and Cabinda (Angola) are left out so routes cannot jump through a country, the short Zambia–Botswana border at Kazungula is added by hand, Morocco–Mauritania is added because the map draws Western Sahara as part of Morocco, and Spain–Morocco (only via the Ceuta and Melilla enclaves) is removed. Island countries without land borders are not used. Each question shows two countries that do not border each other and asks for the 1, 2 or 3 countries that connect them over land; any valid chain of that length is accepted. Guess the River / Mountain highlights 83 rivers and mountain ranges on the map. River lines come from Natural Earth's 1:50m "rivers and lake centerlines" layer and mountain ranges from its 1:50m "geographic regions" layer (both public domain), simplified for the browser by scripts/prepare-rivers-mountains.mjs. Ranges are shown with Natural Earth's generalised outlines, so their edges are approximate. Countries listed for each feature are those it crosses or runs along; facts are short general-knowledge notes. https://www.naturalearthdata.com/downloads/50m-physical-vectors/ Odd One Out builds each group from the same local country data used elsewhere in the library: official languages and currencies (country-facts.json), coastline length (rank-facts.json, zero meaning landlocked), land borders (country-borders.json), population and area. Number rules leave a wide margin (for example, more than 100 million people against fewer than 50 million) so the odd country is clear, and a group is discarded when any other rule in the game would single out a different country. Match the Era uses the same dated events as Order the Historical Events. Centuries follow the traditional count (1701–1800 is the 18th century; 500–401 BCE is the 5th century BCE). The Hard stage asks for the decade and only uses events with a precise date from 1500 onward. Create my Flag text layers use 13 ornate fonts from Google Fonts (UnifrakturCook, UnifrakturMaguntia, Grenze Gotisch, Pirata One, Fruktur, New Rocker, Cinzel Decorative, Rye, Monsieur La Doulaise, Mrs Saint Delafield, Pinyon Script, Great Vibes, Ruthie), all under the SIL Open Font License 1.1, stored locally as Latin-subset woff2 files. https://fonts.google.com/ Guess the Year - Map: the 1812 and 1825 maps come from Cliopatria. Cliopatria draws only the settled or organized part of the United States until about 1890, so the game corrects the US to its legal borders (scripts/fix-guess-year-louisiana.py): in 1804, 1810, 1821 and 1825 it includes the Louisiana Purchase (from the 1815 Historical Basemaps outline east of about 110°W), and in 1848, 1861 and 1867 the full contiguous country (from the 1898 map), with the Confederate States kept separate in 1861 (all of Texas included, Cliopatria's Confederate Arizona dots removed). In 1804 the feature Cliopatria labels "French Louisiana" is split into independent Haiti and the French Lesser Antilles. The 1600 map is Historical Basemaps with the Spanish Empire's American territory taken from Cliopatria 1600 and Portuguese Brazil split off it (scripts/fix-guess-year-1600.py), because the basemap left Iberian colonization out of South America. Add ?test=americas (or europe, asia, africa) to the URL to play every map of one region in order. Guess the Year - Map, Ancient World (the last stage): 16 Cliopatria maps from 490 BC to 1453, framed from Europe to China. Borders this old are approximate and areas with no mapped state are left empty. The Line draws random straight lines on the Natural Earth country map (public/countries.json). A country counts when the line runs at least 2.5 map units (about 2.5° of longitude) inside it; lines that only graze a country, or cross a territory that is not one of the 195 playable countries or is too small to see, are discarded and redrawn. Lines never cross a country's overseas parts (land more than 60 map units from its main territory, such as French Guiana for France), because the whole country would light up far from the line. Word Origin has more than 200 loanwords for each of six languages (English, Portuguese, Spanish, French, German and Italian), split into three stages by difficulty. Only origins given without hesitation by the dictionaries are used; words whose source is disputed (for example tobacco, bamboo or Portuguese minhoca) are left out. Each answer is the language the word was borrowed from, as given by the standard etymological dictionaries: the Oxford English Dictionary and the Online Etymology Dictionary (English), Houaiss (Portuguese), the Real Academia Española's Diccionario de la lengua española (Spanish), the CNRTL/TLFi (French), Kluge and the DWDS (German) and Treccani (Italian). When a word passed through another language (for example Nahuatl xocolatl via Spanish) or has a deeper source (Arabic as-sukkar, ultimately from Persian and Sanskrit), those languages are shown in the answer and never offered as wrong options. "Old Germanic" covers Frankish, Gothic and Lombard, the early Germanic languages that lent words to French, Spanish and Italian. Who Ruled When? uses reign and term years for 13 countries (England/the United Kingdom, the United States, France, Brazil, Russia, Spain, Portugal, Germany, the Habsburg monarchy, the Ottoman Empire/Turkey, Mughal India, China and Japan), checked against Encyclopaedia Britannica and the official lists of each office. Republics list the person who led the country: the president, or the chancellor or prime minister where that was the leading office (Germany after 1949, Salazar's Portugal), and the paramount leader in the People's Republic of China. A question year is always strictly inside one ruler's span and covered by no other listed ruler, so years of transition, regencies and gaps between listed rulers are never asked. Subnational Flags uses the current flag (Wikidata property P41, statements without an end date) of the first-level divisions (P150) of 14 countries, and of their largest cities (over 250,000 people, P1082) that have a flag of their own. Images are 320 px renderings from Wikimedia Commons; each entry in public/subnational-flags.json keeps the Commons file, its licence (public domain, CC0, CC BY or CC BY-SA) and author, and the game links to the file page after each answer. Cities whose flag is the same as their state's (Berlin, Brasília, Zürich), parts of a listed city (New York's boroughs) and territories that simply use the national flag are left out. Mexico lists only the 14 states that have an official flag. Rebuild with npm run prepare:subnational-flags. Higher or Lower compares two countries on one of twelve figures already used by Guess the Country and Rank the Countries (population, area, GDP and HDI from country-facts.json; life expectancy, median age, coastline, highest point, internet users, forest cover, UNESCO World Heritage sites and urban population from rank-facts.json), with the same sources and years. Pairs are only asked when one figure is clearly larger: at least twice the other at the start, then 1.5, 1.25 and finally 1.12 times as the player's number of right answers grows. Guess the Country time zone clue: standard UTC offsets of the time zones each country uses, from the IANA time zone database (tzdata, zone.tab), ignoring daylight saving time. Countries with several zones show the range from west to east. Unofficial local times listed by tzdata are left out (Xinjiang time in China, Eucla time in Australia). Rebuild with npm run prepare:timezones. Guess the Flag – Historical uses flags of former countries: Wikidata items that are a "historical country" (Q3024240) or one of its subclasses, have an end date (P576) and a flag (P41), ranked by their number of Wikipedia articles (the 400 best known are used: the first 70 form the Easy stage, the next 120 the Normal stage, the rest the Hard stage). Images are 320 px renderings from Wikimedia Commons, with licence and author kept in public/historical-flags.json. Left out: Nazi Germany and the Confederate States, Nazi-era puppet states and flags of armed movements, flags identical to a current country's flag, and repeated flags (only the best-known state keeps a flag several states used). In the first two stages, only one Soviet republic is offered at a time, because their flags are nearly identical. Rebuild with npm run prepare:historical-flags. Guess the Anthem plays the first 20 seconds of each country's national anthem (leading silence removed, short fade-out), cut from the recording that Wikidata links to the anthem (P51). Most recordings are public-domain performances by the United States Navy Band; the licence and performer of each one are kept in public/anthems.json and shown after each answer. Countries without a recording on Wikimedia Commons are not included. The Easy stage uses the 30 largest economies, the Normal stage the other countries of Europe and the Americas, and the Hard stage the rest. Rebuild with npm run prepare:anthems (needs ffmpeg). Ultimate Challenge is a run of ten multiple-choice questions, each built from the data of a different game of the library (flags, capitals, country outlines, historical flags, landmark drawings, national emblems, subnational flags, historical events, rulers, word origins and population figures), so every answer follows the sources listed above for that game. Each question lasts 15 seconds and a correct answer scores the seconds left × 10 (1,500 points at most). Profiles use one scoring standard for every game: each finished game is worth 0 to 1,000 profile points, equal to 1,000 × (points scored ÷ the most that game could have given); the profile total is the sum of all games played. A win means completing a game's whole journey, or at least half of the points in single-run games. Signed-in players can add friends by friend code; friends see each other's name, flag, points, games played, wins and most played game, and e-mail addresses are never shown. Accounts: General Knowledge keeps its own accounts (e-mail, name and a salted PBKDF2-SHA256 hash of the password; never the password itself) in the site database. Password-reset links are sent by e-mail through Resend when the site is configured with a mail key. Name Them All uses the playable countries of the Natural Earth map (public/countries.json), grouped into Africa, the Americas, Asia, Europe and Oceania from the map's regions. A typed name counts in the chosen language or in English, plus a hand list of common alternative spellings; accents, capitals and punctuation are ignored. The clock is one minute plus five seconds per country. Who Said It? uses a hand-made list of famous sentences (lib/who-said-it.ts). Only sentences with a solid attribution are included: a dated speech, a book, a letter, or an ancient source that names the speaker; the source is shown after each answer. Popular but wrongly attributed sentences are left out. Translations are the usual wording in each language. The list has 500 sentences; the sentences, dates and translations were written by hand and have not been checked against a second source. When the person is in the historical figures collection, the portrait from that collection is shown after the answer. Road Signs (first called Plates & Signs) uses pictures of road signs from Wikimedia Commons; car licence plates were also collected but are not played, because most show the country's flag or code. The pictures were, chosen by hand (scripts/prepare-plates-signs.mjs); the file page, licence and author of each picture are recorded in public/plates-signs.json and linked after each answer. For the United States, Canada and Australia the plate of one state or province stands for the country. Stop signs that several countries share (for example "PARE", or signs written in Arabic) are not used. The Android robot shown on the home page is reproduced or modified from work created and shared by Google and used according to terms described in the Creative Commons 3.0 Attribution License. Android is a trademark of Google LLC. Higher or Lower uses twenty statistics. Besides the stored figures it derives population density (population ÷ area), GDP per capita (GDP ÷ population), CO₂ emissions per capita (emissions ÷ population) and the number of land borders from the same data files. For average temperature two countries are compared only when they differ by at least 10, 6, 4 or 2 °C according to the level. Left out by hand: the Human Development Index of Monaco and North Korea (not published by UNDP) and internet users of North Korea (the World Bank's 0% is a placeholder). Zoom City ranks cities by the GDP of their country and their population; Taiwan's GDP comes from the IMF World Economic Outlook, because the World Bank does not publish it, and cities of a country without any GDP figure are ranked by population alone. Guess the Flag – Historical: the start years of the Socialist Federal Republic of Yugoslavia (1945) and of the Swedish Empire (1611) come from Wikipedia, because Wikidata has none. Years before Christ are stored as Wikidata shows them (37 BC for Goguryeo). Flags that look the same as another one are marked by scripts/find-alike-flags.mjs and are never options of the same question; states that share a name show their years on the answer buttons. Literacy rate is the World Bank indicator SE.ADT.LITR.ZS (adults aged 15 and over who can read and write), most recent value from 2010 on; many high-income countries do not report it and have no figure. Olympic medals come from Wikipedia's "All-time Olympic Games medal table" and are kept as two figures, Summer and Winter. The medals of predecessor committees are added to today's country as that page's "including precursors" tables do: the Russian Empire, the Soviet Union, the Unified Team, ROC and OAR to Russia; the United Team and West and East Germany to Germany; Bohemia and Czechoslovakia to Czechia; Yugoslavia and Serbia and Montenegro to Serbia. A country with a committee and no medal counts as zero. Both are used by Higher or Lower, Rank the Countries and Odd One Out.