guards need their position inside a pair of waypoint boxes (else the game removes them): placing a guard gives it a box and event bit 0, check and inspector state with box around it button; exit and object checks use the engine's cell rule (tiles listed in the cell, swap models), tile cell from the map loader formula

docs/manual/09-objects.md

@@ -304,18 +304,25 @@ The editor knows the parameters of these types (the rest show raw values):
 | **ForcePlayerMovement**, **WaterReboundPoints**, **ObjectDontDropInBox**, **FallOffNoHurt**, **RiverCurrentBox** | see [Force and water objects](11-cameras-triggers.md#force-and-water-objects) | points / box |
 | **RubyIdolDoor** | Idols needed, Offset (sign distance) | – |
 | **PressurePadDoor** | Pad flags (bit field), Door z, Camera, Camera hold | – |
-| **CityGuard** | View range, Chase range, Event bit, Wall collision | Patrol path (wraps to the first node) |
+| **CityGuard** (and CityGuardWithRubyIdol, CowGuard, GorillaGuard, LizardGuard, WarthogGuard) | View range, Chase range, Event bit (0 = active at once), Wall collision (CityGuard only) | Walking boxes: node pairs; the guard must **start inside one box** |
 | **JumpingBeetleBlue**, **JumpingBeetle** | Jump time, Wait, Jump height, Pause | Jump targets |
 | **Spider** | Range, Speed, Down time, Up time, Start down | Path |
 | **Bunny** | Flee range | – |
 
+> **Guards:** a guard walks around inside the boxes of its waypoint pairs and chases the llama
+> only inside them. If it does not start inside one of its boxes, or the node count is odd, the
+> game removes it when the level starts – it never appears. Placing a guard gives it one 4×4 box
+> around itself and Event bit 0; the Inspector shows a warning and a **Box around it** button
+> when the boxes are wrong. An **Event bit** above 0 keeps the guard hidden until another object
+> with that event number (a talking character, a smash statue, a door pad …) sets the bit.
+
 > **Tip:** For pickups, leave **Snap to floor** on: the game then drops the coin onto the floor
 > when the level starts, so a coin placed slightly too high still ends up in the right place.
 
 ## Duplicating, copying and pasting
 
 * **Edit → Duplicate** (**Ctrl+D**) copies the selection one cell east. Objects keep a copy of
-  their waypoint chain, so a duplicated guard gets its own patrol path.
+  their waypoint chain, so a duplicated guard gets its own walking boxes.
 * **Edit → Copy** / **Paste** (**Ctrl+C** / **Ctrl+V**) work inside the open level.
 * **Delete** removes objects; waypoint chains used only by the deleted objects are removed too.