How Robbers Think: Vision Cones in Catch the Robber
Every robber in Catch the Robber follows a small set of rules. They are simple on their own, but together they make the thieves feel alert and a little unpredictable. Once you understand them, you stop being surprised by robbers who "suddenly" run away, and you start setting up clean sneak catches on purpose. This article explains, from the design side, how a robber sees, how they get suspicious, and how they decide where to run.
The vision cone: what a robber can see
The yellow shape in front of each robber is their field of view. It is a wedge about 70 degrees wide — roughly 35 degrees to each side of the direction they are facing. Anything outside that wedge, including everything directly behind them, is invisible to them.
The cone also has a limited length. On the first level it reaches about four and a half street tiles, and it grows a little with every level until it reaches just over six tiles. A street tile is the width of one road, so you can use the roads themselves as a ruler.
Walls block everything
Buildings and parks are solid. The game checks the straight line between the robber and the sheriff, and if any building is in the way, the robber cannot see you — even if you are well within the cone's range. That is why the cone on screen is cut off at the edges of buildings: what you see drawn is exactly what the robber can see.
Suspicion: the half-second warning
Robbers do not react the instant you enter their cone. Instead, each one has a hidden suspicion level that rises while they can see you and slowly falls when they cannot.
- When suspicion starts to rise, a yellow ? appears above the robber and their cone shifts from yellow towards orange.
- If you are walking normally, suspicion fills in about a third of a second.
- If you are sneaking, it takes about twice as long.
- When you leave the cone, suspicion drains away gradually — it takes well over a second to disappear completely.
When suspicion is full, the robber is alerted: the cone turns red, a red ! appears, and they abandon whatever they were doing.
Sneaking changes two things
Holding Shift (or tapping the Sneak button on mobile) makes the sheriff move at a little over half speed. In exchange:
- Robbers only notice you from about 55 percent of their normal viewing distance. You will see the cones shrink on screen while you sneak.
- Their suspicion grows at half the normal rate, giving you just over half a second to back out of a cone.
Because it is slow, sneaking works best over short distances. Run to within a block of your target, then sneak the last stretch.
The glance: robbers check behind them
A robber who is breaking into a building faces the door, with their back to the street. That makes them the easiest target in the game — but they know it. Every so often they turn around to look behind them:
- They face the building for about one to two seconds.
- Then they turn and look back over the street for about a second, in a slightly random direction.
- On higher levels they glance back a little more often.
The turn is smooth rather than instant, so you can see the cone start to swing before it reaches you. That short warning is enough to stop and wait outside the cone's reach.
Stealing takes time — and matters
An orange progress bar above a stealing robber shows how close they are to finishing. On the first level a break-in takes a bit over three seconds; it gets faster with every level, down to a minimum of just under two seconds.
The progress bar also decides what happens if the robber spots you mid-job:
- Less than halfway done: they flee empty-handed. If they escape, you do not lose a life.
- More than halfway done: they grab the money bag on the way out. If they reach a van now, you lose a life.
So if you are going to be spotted anyway, being spotted early is far better than being spotted late.
Where a frightened robber runs
An alerted robber picks one of the four getaway vans at the edges of the map. They do not simply choose the closest one. Instead they weigh two things: how short the route is, and how far that van is from you. The result is that a spooked robber usually runs away from the sheriff towards a nearby exit on the opposite side.
For the first couple of seconds they sprint faster than you can run on foot — only a donut boost lets you keep pace. After that they get tired and slow down to a jog, which is where most "second chance" catches happen.
Robbers who haven't seen you
Unalerted robbers walk calmly along the streets, facing the way they are going. They choose a building, walk to its door by the shortest route, break in, and then pick a van to escape to. They are slower than you, so catching one from behind on an open street is easy — as long as they don't turn a corner and face you.
Putting it into practice
Everything above adds up to a simple routine: approach from behind, use buildings to block the cone, sneak for the final block, and time your move for when a stealing robber is facing the door. Catch them without being seen and you earn the 100-point sneak bonus on top of the normal catch.
For the basics of scoring and your first level, see our beginner's guide, and for more advanced ideas read the seven stealth tips for a higher score.