Build a library of clues that you’ll use to perform increasingly sophisticated deductions. Through answering questions posed with insufficient information, you’ll also learn how to methodically decide what is and isn’t knowable from a set of premises.

Combine different clue types to solve more complex grids.

The Control Panel

Driving to Conclusions

Managing Duplicates

Configuring Grids

Sharing Information

Using Given Information

Cascading Lights

Patterns of Lights

Using Parity

Rows and Columns

Solve puzzles where the answer includes indicating what isn't known.

Constrain your reasoning to only what is possible to conclude.

Using Unknowns

Insufficient Information

Reasoning with Unknowns

Counting

Use contradictions to slowly rule out possibilities and drive to a solution

Solve puzzles where each step reveals crucial information about the next one

Toggles

Robots Ordering Dessert

Dice Rolls

Opening Safes

Opening Complex Safes

Solve puzzles where there are liars and truth tellers

Use small examples to extrapolate to general principles.

The Rational Detective

Androids

Extrapolate

Unknown Answers

Jokers

Rebels

Use unknown information to eliminate possibilities and drive to solutions.

Multi-Level Thinking

Guessing Cards

Hat Puzzles

Strengthen your deductive reasoning skills by using a variety of logical clues to configure grids.

Build simple computers out of logic gates.