The chaser is the most misunderstood rule in the catalogue — because it sees you, and seeing you does not catch you.
Behaviour
A chaser waits at its post like a sentry. The moment it sees an actor it goes into an alert state and targets whichever node that actor is standing on.
While alert, it advances one edge along the shortest path to that target on every enemy phase. When two paths are equally short, it takes the one whose edge comes first in the level data — so the pursuit is deterministic too, never a guess.
Once it reaches the target it waits until its patience runs out (two turns; this value is fixed, and no level can define another patience), then walks back to its post under the same rules and resets. Seeing you again refreshes the target and resets the patience.
The tension does not come from being spotted at range. It comes from your escape route closing. Walk into a dead end with a chaser behind you and you cannot get back past it.
How you read it
The alert state is unmistakable: an exclamation mark, a colour change, and a change of posture. A question mark sits on the node it is heading for, so you can see where it is going. The patience counter ticks down above the figure.
Taught in
Taught in2-3
This level cannot be passed without taking the chaser into account: no solution that avoids the rule is found within three moves of the shortest solution. The second half of the rule — "its patience runs out and it goes home" — only becomes visible if you are willing to be chased.
What answers it
The first is the hiding spot: an actor on
a hide node is invisible to a chaser too, so the alarm never fires at all. If
it is already on alert, the distraction of a bell stone overrides the alarm and turns it towards
the sound.
If you can get close before the alarm starts, it is also possible to take the chaser down from behind.
The last way is simply to run: a chaser is no faster than you are.