In many Western cultures, which indoor action is traditionally considered unlucky?

In many Western cultures, opening an umbrella indoors is traditionally considered unlucky.

The belief is often explained through practical danger rather than a single ancient myth. Early umbrellas had rigid ribs and awkward mechanisms, so opening one in a confined room could injure someone, knock over objects, or damage furniture. A rule discouraging the action could therefore have been expressed as a warning about bad luck.

Modern retellings sometimes claim that the superstition began in ancient Egypt or with Victorian umbrella marketing, but those origin stories are not firmly established. The custom appears in several European and North American folklore traditions, with wording and strength varying by household.

An umbrella opened indoors has no demonstrated supernatural effect. It can still be inconvenient or hazardous in a crowded room, especially around children, glass objects, or low ceilings. The superstition is therefore a good example of a practical caution acquiring symbolic meaning.