Geography
Capitals and flags for all 195 countries, the 193 UN members plus Vatican City and Palestine. Both games draw fifteen a round, and the wrong answers come from the same region.
Why these are harder than they look
Capitals of the World asks for one city per country, which is a simplification for 22 of them. South Africa has three capitals, Bolivia and the Netherlands split the job between two cities, and Switzerland has never named one in law. The page under the game lists every one of those cases and how the quiz treats it.
Flags of the World puts lookalikes side by side on purpose. Chad and Romania differ only in the shade of blue, Indonesia and Monaco only in proportions, and Norway and Iceland swap the same two colours. Twelve groups like that cover 31 flags, and when one of them comes up, its twin is among the four options.