Making an Accusation
Why People Get This Wrong
People often assume you can only make an accusation after secretly inspecting all three cards, which leads them to overlook that they can stop at any point if two match early, thus saving a secretive inspection for when it's absolutely necessary. The confusion arises because the rule doesn't specify whether you must inspect each card individually or just collectively before deciding to accuse.
Official Verdict
Secretly inspect the three solution cards without showing them to anyone. If all three match, reveal them and win.