There are no laws as such in the Culture. Social norms are enforced by convention (personal reputation, 'good manners' and by, as described in The Player of Games, possible ostracism and involuntary supervisionfor more serious crimes). Minds generally refrain from using their all-seeing capabilities to influence people's reputations, though they are not necessarily themselves above judging people based on such observations, as described in Excession. Minds also judge each other, with one of the more relevant criteria being the quality of their treatment of sentients in their care. Hub Minds for example are generally nominated from well-regarded GSV (the largest class of ships) Minds, and then upgraded to care for the billions living on the artificial habitats.

The only serious prohibitions that seem to exist are against harming sentient beings, or forcing them into undertaking any act (another concept that seems unnatural to and is, in fact, almost unheard of by almost all Culture citizens). As mentioned in The Player of Games, the Culture does have the occasional "crime of passion" (as described by an Azadian) and the punishment was to be "slap-droned", or to have a drone assigned to follow the offender and "make sure [they] don't do it again".

While the enforcement in theory could lead to a Big Brother-style surveillance society, in practice social convention among the Minds prohibits them from watching, or interfering in, citizens' lives unless requested, or unless they perceive severe risk. The practice of reading a sentient's mind without permission (something the Culture is technologically easily capable of) is also strictly taboo, and Minds that do so are considered deviant and shunned by other Minds (see GCU Grey Area). At one point it is said that if the Culture actually had written laws, the sanctity of one's own thoughts against the intrusion of others would be the first on the books.

This gives some measure of privacy and protection; though the very nature of Culture society would, strictly speaking, make keeping secrets irrelevant: most of them would be considered neither shameful nor criminal. It does allow the Minds in particular to scheme amongst themselves in a very efficient manner, and occasionally withhold information.