Vault Heist Game

You are a thief in a museum at night. The lights are on for a few seconds while you study the room, then they go out and a guard walks in. When they come back on, something has changed, and you have to find it before the guard's torch beam reaches you. It is Kim's game, the classic test of observation, played against the clock.

How to play

1. Study the room while the lights are on. It has five plinths and three picture frames, and the banner counts down the seconds.
2. The lights go out and a guard walks in from the door. All you can do is wait.
3. The lights come back with something changed, and the guard's torch beam starts across the floor toward you. Tap the plinth or painting that changed. If nothing changed, which happens now and then, tap NOTHING CHANGED.
4. A right answer scores more the further the beam is from you. A wrong tap costs time, and the guard walks faster.
5. If the beam reaches you, the alarm sounds and the room shows what changed. Three alarms end the heist.

Rooms get harder in what changes, not only in how fast. Each new kind of change is announced the first time it appears.

• GONE, from room 1: an exhibit disappears.
• MOVED, from room 3: an exhibit moves to an empty plinth, or a painting to a blank frame. Either place counts as the answer.
• SWAPPED, from room 5: two exhibits or two paintings change places. Either one counts.
• RECOLORED, from room 7: an exhibit turns from gold to silver, or back.
• TWO CHANGES, from room 9: find both before the beam reaches you.

Later rooms also hold more exhibits and give you less time to study, from 5 seconds in room 1 down to 2.5 seconds. On a keyboard, press 1 to 5 for the plinths, Q, W and E for the paintings, and 0 for NOTHING CHANGED. Escape or Space pauses, and pausing hides the room, so it cannot buy study time.

Scoring

Each change you find scores 100, plus up to 200 for how far the beam still has to go, rounded to the nearest 10. Tapping the change the moment the lights come back scores 300, and halfway along the beam's run it scores 200. NOTHING CHANGED in a room where nothing changed scores the same way.

• The beam takes 9 seconds to reach you in room 1, 0.4 seconds less in each room after it, and never less than 4 seconds.
• A wrong tap, or NOTHING CHANGED when something did change, moves the beam 12% of its run closer and makes the guard walk 25% faster for the rest of the room, up to three times as fast.
• When the alarm sounds, the changes you did not find score nothing, but a change you found before it, in a room with two, keeps its points. You play the same room number again with a new layout.

For example, finding a missing crown as soon as the lights come back scores 300, and the tag CROWN GONE +300 shows it. Finding it when the beam is three quarters of the way to you scores 150.

Your five best scores are saved in this browser, with the room each game reached. In practice, the guard always stops short of you, so no alarm sounds and the game never ends on its own. End it from the pause screen. Practice games are not saved.

About Kim's game

Vault Heist is named after a game in Rudyard Kipling's 1901 novel Kim. Kim is trained as a spy with the jewel game: a tray of stones is shown to him for a short time, then covered, and he has to say what was on it. Robert Baden-Powell put the game in Scouting for Boys, and Kim's game became a standard scouting exercise for training observation.

The rooms where things are MOVED and SWAPPED ask for more than a list of what was there. You have to remember where each thing was. That link between an item and its place is what a memory palace is built on, and it goes back to the story of Simonides of Ceos, who named the guests of a collapsed banquet hall by remembering where each one sat.

Read how others play Kim's game in the Kim's game thread on our forum, test yourself with the photographic memory test, or try our other free memory games.