A standard Pokémon booster pack contains 10 game cards, 1 Energy, and 1 code card for the online game. The 10 game cards include a specific distribution of rarities, typically 4 commons, 3 uncommons and 3 foils , with at least one of the foils being a rare or higher rarity. The cards come from a specific, single expansion set and are randomly assorted, so you don't know which cards you will get.