(quantum mechanics) The general name for a vast category of physical problems pertaining to the properties of microscopic systems made of many interacting particles.

The problem that a person or entity serving as an agent for another, and able to make decisions on the other's behalf, may be motivated instead to make decisions that benefit themselves.

Alternative form of first world problem

(graph theory) The problem of finding the longest possible induced path in a hypercube.

(marketing) The situation where a potential consumer looks for the best good or service in an unfamiliar, expensive, or infrequently-bought category, requiring a great deal of research.

The situation where an autonomous robot is carried somewhere and as a result has trouble in determining its own location.

(astronomy) The problem of calculating the motion of three celestial bodies that interact with each other gravitationally

A brainteaser regarding probability, in which a game show contestant picks a door to win a prize. One door conceals a car; the other two conceal goats. After the contestant picks a door, the host opens one of the two remaining doors which reveals a goat. Counterintuitively, it is then in the contestant's interests to switch to the remaining door.

The problem posed by ironic process theory, where (for example) explicitly trying not to think about a white bear makes one more likely to think of it.

A visibility problem in computational geometry, dealing with whether a number of points in a polygon can collectively "see" (by line segments akin to a person's line of sight) the whole interior of the polygon.