--- key: practice/maintenance-patrol type: practice id: maintenance-patrol lang: en title: Maintenance patrol summary: 'Connect perception, memory, action selection and route following.' updatedAt: '2026-10-20' status: active url: 'https://gamemechanics.pro/en/knowledge/practice/maintenance-patrol/' jsonUrl: 'https://gamemechanics.pro/api/v1/knowledge/en/practice/maintenance-patrol.json' markdownUrl: 'https://gamemechanics.pro/content/knowledge/en/practice/maintenance-patrol.md' aliases: [] tags: - NPC behavior sourceIds: - source-3e6c21889ae768e0 - source-6f794a271cd60b9c sources: - id: source-3e6c21889ae768e0 title: 'Challenges for Game Designers: author website' url: 'https://designgames.wordpress.com/' verifiedAt: null - id: source-6f794a271cd60b9c title: 'Challenges for Game Designers: table of contents' url: 'https://designgames.wordpress.com/toc/' verifiedAt: null relations: - type: practices direction: incoming label: What this helps you learn key: lesson/npc-perception title: NPC perception and target memory url: 'https://gamemechanics.pro/en/lessons/npc-perception/' jsonUrl: 'https://gamemechanics.pro/api/v1/knowledge/en/lesson/npc-perception.json' markdownUrl: 'https://gamemechanics.pro/content/knowledge/en/lesson/npc-perception.md' - type: practices direction: incoming label: What this helps you learn key: lesson/npc-action-selection title: How an NPC selects an action url: 'https://gamemechanics.pro/en/lessons/npc-action-selection/' jsonUrl: >- https://gamemechanics.pro/api/v1/knowledge/en/lesson/npc-action-selection.json markdownUrl: >- https://gamemechanics.pro/content/knowledge/en/lesson/npc-action-selection.md - type: practices direction: incoming label: What this helps you learn key: lesson/npc-pathfinding title: Pathfinding and following a route url: 'https://gamemechanics.pro/en/lessons/npc-pathfinding/' jsonUrl: 'https://gamemechanics.pro/api/v1/knowledge/en/lesson/npc-pathfinding.json' markdownUrl: 'https://gamemechanics.pro/content/knowledge/en/lesson/npc-pathfinding.md' - type: practices direction: incoming label: What this helps you learn key: path/npc-behavior title: NPC behavior url: 'https://gamemechanics.pro/en/learn/npc-behavior/' jsonUrl: 'https://gamemechanics.pro/api/v1/knowledge/en/path/npc-behavior.json' markdownUrl: 'https://gamemechanics.pro/content/knowledge/en/path/npc-behavior.md' - type: uses direction: outgoing label: Sources in the selection key: resource/challenges-for-game-designers title: Challenges for Game Designers url: >- https://gamemechanics.pro/en/resources/#resource-challenges-for-game-designers jsonUrl: >- https://gamemechanics.pro/api/v1/knowledge/en/resource/challenges-for-game-designers.json markdownUrl: >- https://gamemechanics.pro/content/knowledge/en/resource/challenges-for-game-designers.md placements: - title: In the original collection url: 'https://gamemechanics.pro/en/practice/#maintenance-patrol' supersededBy: [] attributes: topic: npc level: intermediate minutes: 90 endsAt: null provenance: >- Thematic inspiration: Challenges for Game Designers by Brenda Brathwaite and Ian Schreiber. These scenarios, constraints and checks are independently written around broad game-design learning topics. This is not a translation or a sequential retelling of the book exercises. license: CC-BY-4.0 codeLicense: MIT attribution: gamemechanics.pro contributors --- # Maintenance patrol id: maintenance-patrol type: practice key: practice/maintenance-patrol lang: en status: active url: https://gamemechanics.pro/en/knowledge/practice/maintenance-patrol/ Connect perception, memory, action selection and route following. ## Goal Connect perception, memory, action selection and route following. ## Scenario and materials A robot patrols a station, detects a fault and moves to repair it. A door may close between it and the target. Store the robot’s known target position separately from the actual world state. A small scene or step-by-step model with an event log ## Constraints - Use one map, one robot and one fault. Specify the graph and edge costs explicitly. - The robot learns through observations only; its memory expires. - Every action change logs time, observation and reason. ## Steps 1. Define patrol, move-to-fault, repair and search states, including transition conditions. 2. Separate observations from memory. Losing sight must not instantly reveal the target’s new position. 3. Connect action selection to path search and movement; recompute after a closing door or return an explicit failure. 4. Repeat these scenarios: visible target, lost target, closing door and unreachable target. Preserve identical starting conditions. ## Deliverable A runnable scene or reproducible step-by-step model, map, transition table and four logs explaining decisions. ## Check your work - Identical starting conditions and observations produce identical decisions. - After losing sight, the robot uses the last known position until memory expires. - A closed door causes neither wall traversal nor endless path recomputation each frame. - Target reached, no route and start equal to goal are distinguishable results. ## Reflect Which wrong decision came from memory, which from priorities and which from navigation? Change only one of these layers. ## Connected materials - What this helps you learn: [NPC perception and target memory](https://gamemechanics.pro/en/lessons/npc-perception/) (key: lesson/npc-perception) - What this helps you learn: [How an NPC selects an action](https://gamemechanics.pro/en/lessons/npc-action-selection/) (key: lesson/npc-action-selection) - What this helps you learn: [Pathfinding and following a route](https://gamemechanics.pro/en/lessons/npc-pathfinding/) (key: lesson/npc-pathfinding) - What this helps you learn: [NPC behavior](https://gamemechanics.pro/en/learn/npc-behavior/) (key: path/npc-behavior) - Sources in the selection: [Challenges for Game Designers](https://gamemechanics.pro/en/resources/#resource-challenges-for-game-designers) (key: resource/challenges-for-game-designers) ## Sources and provenance Thematic inspiration: Challenges for Game Designers by Brenda Brathwaite and Ian Schreiber. These scenarios, constraints and checks are independently written around broad game-design learning topics. This is not a translation or a sequential retelling of the book exercises. - [Challenges for Game Designers: author website](https://designgames.wordpress.com/) (id: source-3e6c21889ae768e0) - [Challenges for Game Designers: table of contents](https://designgames.wordpress.com/toc/) (id: source-6f794a271cd60b9c) CC-BY-4.0 · gamemechanics.pro contributors