How does a colloquium doctum work?

A colloquium doctum is a special admission procedure for people who cannot directly be granted admission to a university programme on the basis of their diploma, and who are aged 21 or older. It involves completing tests in a number of subjects at pre-university (VWO) level. Successfully completing a colloquium doctum at Leiden University only grants access to Leiden University and only to the specific programme for which you were tested.