Free diagnostic reasoning game
Start with simple cases that help you decide what to ask, check, or rule out next. Each case keeps the answer hidden until you make the final call.
Starter library
Several people in one home feel tired and headachy, so the first guess might be a routine seasonal illness. This starter DxDetective case asks you to slow down, compare who feels worse, where symptoms change, and which clues make the household pattern matter.
Dedicated to school nurses and coaches who ask one more good question.
A small foot injury can look easy to handle, but the useful questions come from the story around it. This starter DxDetective case asks you to slow down, ask what happened, compare simple observations, and decide whether basic care is enough or the next step should escalate.
Dedicated to students who report small changes before they become big ones.
A student has one red, uncomfortable eye after practice and wants a quick answer. This starter DxDetective case asks you to slow down, check for warning signs, ask targeted questions, and decide whether the problem can wait or needs eye-specific guidance today.
Jay Lopez is late getting out of the car after a long summer practice. His aunt Mara expects complaints about sore muscles, but by breakfast he needs the banister and leaves his gear by the door.
Leah Morgan notices a small skin mark on Owen’s shoulder while they unload muddy camping gear. Three days later, he skips breakfast, says he is tired, and asks if he can stay home.
Rosa Bennett is rinsing the last dishes from a family dinner when her brother Miles calls from the hallway. He felt fine when everyone left, but hours later he is pale, uncomfortable, and trying to remember what changed.
Ari Patel is halfway through sliced pears when he pushes the plate away. His mother, Priya, wipes his chin and notices he is drooling more than usual.
Noah Nguyen has been at the kitchen table all afternoon, building a tiny craft project while his mother Tessa answers email nearby. Then he goes quiet.
Samira Cole expects Milo to trot after the last guest, nose high for a goodbye and any dropped ice cubes. Instead, he stays under the coffee table.
Nia Robinson is closing up the yard at dusk when she notices a faint movement at the surface of the rain barrel behind the shed. The air is still.
Inez Flores waits out two days of rain before stepping onto the patio with her morning coffee. Her favorite planter, usually upright against the railing, is bent low and looks spent.
Devon Price wakes at 2:13 a.m.
June Navarro opens the winter water bill twice because the first number cannot be right. Eli Navarro looks over her shoulder and starts naming the usual suspects: visitors, extra laundry, holiday cooking.
Shelby Khan reaches into the freezer for a bag of vegetables and finds a new layer of frost along one side. Omar thinks it is just the aftermath of a busy weekend: people came over, food was shifted around, and the kitchen never quite caught up.
Harper Dean wakes before dawn because the bedroom feels colder than the rest of the home. In the hallway, the air feels normal.
Ruth Collins sends her brother Sam a birthday card just after he moves. A few days later, the card is back on her front step with a short mark on the envelope.
Anna Okafor brings a box of family keepsakes to the kitchen table on a rainy Saturday, planning a quiet afternoon with her nephew Theo. They laugh over the box's old labels until Anna tries to lift one glossy layer and finds that it will not come apart cleanly from the next.
Kira Owens notices the closet smell when she reaches for a coat after a rainy week. It is faint, unfamiliar, and gone by the time Daniel gets home.
Marisol Vega has kept the trailing houseplant by the living-room shelf for years. When she moves it into a larger blue pot, Ben jokes that it finally has room to spread out.
Hannah Brooks reaches into the pantry for breakfast and pauses over a package that looked ordinary last week. Inside, there are fine strands and small bits near one fold.
Maya Alvarez sees clear beads on the glass beside her bed during the season’s first cold morning. Across the hall, Peter’s room looks ordinary.
Elena Ortiz thought Nico was back to normal. He gets through school one day, runs an errand with her afterward, and says he is fine.
Lena Foster is three blocks into the evening walk she and Marcus have taken for years when he stops at the familiar hill. “Give me a minute,” he says, leaning on the rail.
Maya Patel is still learning the rhythm of the playground when Quincy Brooks leaves a running game early and leans against the fence. He says he just needs a minute, but he is taking longer than usual to answer her.
Rosa Ellison is collecting cupcake wrappers when Nia Walker quietly says that her mouth feels strange. A few red patches have appeared on Nia's arms.
Daniel Lee has seen plenty of ordinary playground tumbles. Omar Reed usually brushes them off faster than anyone.
Erin Gardner notices Mateo Santos before the lunch line does. He has been talking through the morning, but now he is staring at his desk, rubbing his hands together, and asking whether he can sit down.
Field Day has been noisy since morning, and Terrence Bell has spent the last hour counting teams, sunscreen bottles, and water breaks. Near the end of the relay races, Amara Ford steps out of line and bends over with both hands on her knees.
Elena Ochoa has just settled her class into reading circle when Imani Wells begins scratching at the back of her head. It happens once, then again, and soon Imani is trying to hide behind the hood of her sweatshirt.
Answer vocabulary
These final-call phrases come from published DxDetective cases. They are listed only as a library-wide set, so they do not show which case each answer solves.
New cases
Practice what to check first, what details to track, and when it is safer to ask for outside help.