be picked out of a hat

be picked out of a hat

To be selected entirely at random. A reference to the practice of making a random selection by literally choosing from a collection of items in a hat, typically scraps of paper on which names have been written. I don't understand why our company is being targeted. It's as if we were picked out of a hat by the IRS! It doesn't really matter who gets promoted to assistant manager—a name can be picked out of a hat for all I care!
See also: hat, of, out, picked
Farlex Dictionary of Idioms.

be picked out of a hat

If a name or an entry in a competition is picked out of a hat, it is chosen randomly, often by choosing a piece of paper from a container, so that each one has an equal chance of being chosen or winning. All you have to do to win is answer this question correctly and hope you get picked out of the hat. Note: Other verbs, such as draw or pull, are sometimes used instead of pick. The first 10 correct entries drawn out of the hat will win a pair of tickets, worth £20 each.
See also: hat, of, out, picked
Collins COBUILD Idioms Dictionary, 3rd ed.
See also:
  • random
  • at random
  • by lot
  • pull (someone or something) out of a hat
  • pull out of a hat
  • pick (someone or something) out of a hat
  • pick something out of a hat
  • pick, etc. something out of a hat
  • your/somebody's number comes up
  • (one's) number comes up