Rule of three or Rule of Thirds may refer to:

Science and technology

  • Rule of three (aeronautics), a rule of descent in aviation
  • Rule of three (C++ programming), a rule of thumb about class method definitions
  • Rule of three (computer programming), a rule of thumb about code refactoring
  • Rule of three (hematology), a rule of thumb to check if blood count results are correct
  • Rule of three (mathematics), a method in arithmetic
  • Rule of three (medicinal chemistry), a rule of thumb for lead-like compounds
  • Rule of three (statistics), for calculating a confidence limit when no events have been observed

Arts and entertainment

  • Rule of three (writing), a principle of writing, and of rhetoric
  • Rule of Three, a podcast by Jason Hazeley and Joel Morris
  • Rule of Three, a series of one-act plays by Agatha Christie
  • The Bellman's Rule of Three in The Hunting of the Snark, a poem by Lewis Carroll
  • The Rule of Thirds, a 2008 album by Death In June
  • Rule of 3, alternate title of Canadian 2019 TV movie All my husband's wives
  • Rule of Three (film), an upcoming Temple Hill Entertainment horror film based on Sam Ripley's novel of the same name

Other uses

  • Rule of threes (survival), a mnemonic for the priorities of survival
  • Rule of Three (Wicca), a religious tenet

Variations

  • Rule of thirds, a rule of thumb for composing visual images
  • Rule of thirds (diving), a rule of thumb for divers
  • Rule of thirds (military), a rule of thumb in military planning

See also

  • Three-sigma rule, for a normal distribution in statistics
  • Triumvirate, a political regime dominated by three powerful individuals