The bell stone changes the board from a distance; the takedown changes it up close. It has no button of its own and no command of its own: you walk onto an enemy's node, and the direction you enter from decides the outcome.
Behaviour
The rule is two sentences: if you walk onto an enemy's node from any direction other than the one it is facing, you take it off the board. You cannot touch a chaser on alert, or two enemies standing on the same node.
The direction an enemy faces is the neighbouring node it is looking at. Come from that neighbour and you step right into its face, and the result is capture; come from any other neighbour and the enemy is taken down. The rule reads like this for each type of enemy:
- Sentry. The neighbour it faces is its "front". Coming from the front is capture; coming from any other direction is not.
- Rotating sentry. The heading visible on the board while you make your move is the one that counts, not the heading it will turn to at the end of the turn. The broken ring on its base already shows the next heading, but you plan your move against today's one.
- Patrol. The direction it faces is the next node on its route. Coming from the node the patrol is heading towards is coming from the front; coming from behind or from the side is not.
- Chaser. While it waits and while it returns to its post, it can be taken down like the others. On alert it cannot be taken down: stepping onto its node is capture.
- Distracted enemy. An enemy turned towards the sound of a bell stone can be taken down from any direction; it is already looking at the sound.
A few more limits surround the rule:
- One enemy. If a node holds more than one active enemy, the result is capture; you cannot take them down one by one.
- No chain reaction. A downed enemy takes no part in the enemy phase, in sight, or in contact. Taking one down does not put the others on alert.
- Hiding spot. Stepping from a
hidenode onto an enemy's node is allowed and the rule works as usual. Enemies never step onto a hiding node, so no one can be taken down there. - Stone. The stone takes down no one; it only lifts the direction restriction for the enemy it distracts.
- Door and one-way edge. You cannot come through a closed door or against the direction of a one-way edge; no extra rule is needed for that.
- Caravan members. Only the caravan leader can take an enemy down. If a member steps onto an enemy's node, the result is capture. See Caravan members.
The only way to bring a downed enemy back onto the board is to undo. So you can learn the rule by trying it; a wrong approach costs one click.
How you read it
A downed figure leaves the board and sits in the "Taken down" tray. The tray is also a counter: you see there how many enemies you have taken in the level. The figure in the tray is seated; there is no violent imagery — as in the rest of the game, no one hurts anyone.
An enemy's front direction is already painted in the threat colour. To see the outcome of a move, you can preview it: when you point at the target node, the result comes from the same calculation as the engine's turn resolution, and the enemy about to be taken down is marked with a "hand" icon; if you are about to be caught, that is written out too. The preview can be switched off with the "Move preview" toggle in the settings. A chaser on alert, meanwhile, carries an "untouchable" frame next to its exclamation mark.
Taught in
Taught in1-1
The rule is introduced together with the sentry in the first level of the act, and the second level reinforces it right away. In the tutorial levels, no solution that avoids the rule is found within three moves of the shortest solution; so the takedown comes at you not as an option but as the path itself.
A validation rule
The number of enemies that can be taken down per level is four at most. The reason is the solver's budget: each enemy that can be taken down at most doubles the level's number of reachable states. The limit may be loosened based on measurements.
Relation to stars
Two bonus goals are built on this rule: finishing without taking anyone down, and taking down every enemy in the level. The details are on the Stars page.