draw straws
verb
Definitions
To decide at random by drawing (selecting randomly between) straws, sticks, etc., one of which differs from the others (typically by being shorter), held in a person's hand so as to conceal which is the different one. Typically, whoever draws the short straw must complete some undesirable task.
Example: They drew straws to see who had to wash the dishes.
(by extension) To decide by any means of chance.