Every October, the world watches Stockholm and Oslo as the Nobel Prizes are announced. But how are the winners actually chosen? The process is secretive, slow and deliberately insulated from lobbying.

Each prize has its own selector. The Nobel Assembly at Karolinska Institute picks the medicine laureate. The Royal Swedish Academy of Sciences chooses physics, chemistry and economics winners. The Swedish Academy awards literature, and a committee appointed by Norway’s parliament awards the peace prize.

Thousands of qualified nominators, from university professors to former laureates, submit names. The rulebook bars self-nomination and posthumous awards. Nominations stay sealed for 50 years, which is why speculation is never confirmed.

Committees spend months reviewing candidates with the help of expert reports. Decisions are made by majority vote in the autumn, and the announcement dates are fixed in advance. This year’s announcements run from October 5 to October 12, with winners receiving 12 million Swedish kronor each.