Hermione Granger got it right when, facing the potion-master's test in Harry Potter, she said: "This isn't magic - it's logic - a puzzle. A lot of the greatest wizards haven't got an ounce of logic; they'd be stuck here forever." - Harry Potter and The Sorcerer's Stone. If you are a middle school student or a high school student, prove that you are a logical wizard. Sign up for the International Logic Olympiad. (Click the Registration link above.) Demonstrate that you can outsmart the illogical wizards of Harry Potter.

The International Logic Olympiad (ILO) is a world-wide competition on Logic. The competition is broad-based - since its inception in 2024, we’ve reached students from 2100+ schools across 90+ countries. This year, there are two separate competitions. The Junior Logic Olympiad (JLO) is intended for middle school students. The Senior Logic Olympiad (SLO) is intended for high school students.

Each competition (JLO and SLO) consists of an online qualifying quiz in the Spring at regional test centers followed by an in-person final exam administered in the Summer on the Stanford University campus.

The questions on the quiz and the final exam test the participants' understanding of Logic in a variety of ways - through questions about logical concepts (such as logical consistency and logical entailment), through abstract problems requiring logical reasoning techniques (such as logic grids and proofs), and through concrete applications of Logic in puzzles and games and real life problems.

To help students prepare for the competition, the Olympiad provides access to Stanford's introductory course on Logic. The course materials are available online, open to all, and free of charge. (Click the Course link to get started.) There are also practice tests to give potential participants a sense of the kinds of questions on the qualifying tests. (Click the Junior Practice Test and Senior Practice Test links above to access the tests.)

The Olympiad depends on organizations around the world to host regional qualifying competitions. If you are interested in hosting a competition in your area, click on the Partners link above for details.