Photo: James Bareham/Polygon
Pokémon Go has basic missions that players can complete in exchange for Pokémon encounters, items, and Stardust. They’re called Field Research Tasks.
Spinning Pokéstops will give players a Field Research Task to complete. Each stop will give a task once a day and players can hold up to three tasks at once. Upon completing a task, players will get a stamp marked with the date. After getting seven stamps from seven different days, players will encounter a special Pokémon, as well as get Stardust, items, and some XP as rewards. Players can turn in multiple tasks a day, but will only receive one stamp for the first task they complete that day. Note that after completing a task, you can wait to turn it in, if you want to save the stamp for another day.