The Player of Games

The Minds — superintelligent ship and habitat AIs administering a galactic civilisation.

Compose, study, design ships that will never be built, gland recreational drugs, play games at a professional standard. A small minority join Contact, because interfering with less advanced civilisations is the only remaining source of real risk.

Play as vocation — Work becomes hobby, and the serious people go looking for risk on purpose.

Read this rather than Consider Phlebas. It is the entry point that actually argues the Culture's case.