"A = A"
— The law of identity, the first of the three classical laws of thought
An index of tropes having to do with logic. As you can see, many of these tropes detail ways in which writers can fail at logic. For some reason, there aren't nearly as many about correct logic...
Compare Intelligence Tropes. Contrast Madness Tropes and Emotion Tropes, which frequently defy logic in various ways.
Tropes:
See also:
- 2 + Torture = 5
- Arkham's Razor (In fiction, the oddest solution is probably correct)
- Bat Deduction
- Catch-22 Dilemma (You have to do A in order to do B, but you have to do B in order to do A.)
- Chicken-and-Egg Paradox (A leads to B which leads to A which leads to B, but how did it start?)
- Deducing the Secret Identity: (Using logic to figure out who a masked hero or villain really is.)
- Entertainingly Wrong (When somebody is wrong, for the right reasons.)
- Fact/Opinion/Argument
- Fridge Logic (Logic problems that are only noticeable when you think a bit about them)
- Game of Chicken
- Giving Up on Logic
- If Jesus, Then Aliens
- Insane Troll Logic (When fallacies are either intentional, or they cross over into Poe's Law.)
- Justified Trope (When use of a trope is made logical)
- Liar's Paradox
- Logic Bomb (Using fallacies, paradoxes, and other logical quibbles as a weapon)
- Moon Logic Puzzle (A puzzle whose solution relies on overly narrow or unconventional interpretations of the available evidence)
- Mutually Assured Destruction
- Occam's Razor (Explanations should avoid unnecessary complications.)
- Prisoner's Dilemma
- Puff of Logic
- Reasoning with God
- Reminder of Impossibility
- Right for the Wrong Reasons (When you reach the correct conclusion, but by faulty logic.)
- Sherlock Can Read
- So Crazy, It Must Be True
- The Spock