If you’ve ever wondered how hard it really is to become an FBI agent, just take a look at the logic tests they use. More than 95% of candidates fail. These aren’t your average multiple-choice questions or vocabulary drills. Instead, the FBI uses riddles and scenarios that demand critical thinking, sharp intuition, and the ability to step outside the box. These puzzles aren’t just meant to confuse—they reveal who can think like a detective, catching what others miss.

One of the most famous of these is the “Killer’s Two Pills” riddle. In this brain teaser, a serial killer captures victims and offers them two pills. He claims one is harmless and the other is deadly, allowing his victims to choose first. Strangely, no matter which pill the victim picks, they always die. The killer, taking the remaining pill, survives every time. So how is he not dropping dead too? The trick is in the glass of water. Both pills are actually safe—the poison is hidden in the victim’s drink. This riddle teaches a valuable lesson in misdirection: sometimes, the danger isn’t in what you’re told to examine, but in what you’re not.

Another classic puzzle is called “Who Is the Child’s Mother?” In this scenario, you’re shown a picture of two women sitting across from each other while a child plays on the floor. The question is simple—who is the child’s mother? Most people get it wrong. The key lies in body language and instinct. The real mother is the one who naturally faces her child. She’s positioned in a way that suggests protection, readiness to respond if the child needs her. Even subtle cues—like the way her legs are angled or how engaged she looks—can reveal the truth. This puzzle is about understanding human behavior and reading nonverbal clues, which is critical for law enforcement work.

Then there’s the chilling “Scary Drinks” scenario. A man and a woman are both served drinks with ice. The woman gulps down four glasses quickly and lives. The man sips his single drink slowly and dies. At first glance, it seems totally unfair or random. But the explanation is pure genius: the poison was in the ice, not the drink itself. Since the woman drank quickly, the ice didn’t have time to melt. The man, however, gave the poison enough time to mix into his beverage. This riddle highlights the importance of thinking about time, temperature, and chemistry—details that a sharp investigator wouldn’t overlook.

Another memorable test is the “Cassette Player Mystery.” In this puzzle, a man is found dead with a gun in one hand and a cassette player in the other. The police arrive and play the tape, which contains a suicide message. Case closed? Not quite. A seasoned detective thinks twice. If the man recorded his suicide note, how did the tape end up rewound? After all, someone who just shot themselves wouldn’t be able to rewind a tape. That tiny detail—the position of the tape—blows the whole story wide open. It suggests someone else was there, tampering with the scene to stage a suicide. This one’s all about noticing what others ignore. In a real investigation, a single overlooked fact could mean the difference between justice and a cold case.

Each of these riddles may sound like a game, but they have real-world value. They train your mind to look deeper, to ask the right questions, and to not take anything at face value. In the world of criminal investigations, suspects lie, evidence is planted, and situations rarely unfold in a straight line. The ability to detect patterns, challenge assumptions, and remain curious under pressure is what separates great agents from the rest.

So, do you think you could pass the test? The next time you face a tricky situation—whether it’s solving a mystery or just making a tough decision—try thinking like an FBI agent. Look beyond the obvious. Trust your instincts. And remember, the answer is often hidden in plain sight.