{"schemaVersion":1,"record":{"key":"mechanic/phone-flashlight--family-multiplayer","type":"mechanic","id":"phone-flashlight--family-multiplayer","lang":"en","title":"Cooperation, competition and communication","summary":"Light carries a signal to another participant. Morse-It encodes text as flashes for a person in line of sight; automatic reception is not implied.","updatedAt":"2026-10-22","status":"active","url":"https://gamemechanics.pro/en/knowledge/mechanic/phone-flashlight--family-multiplayer/","jsonUrl":"https://gamemechanics.pro/api/v1/knowledge/en/mechanic/phone-flashlight--family-multiplayer.json","markdownUrl":"https://gamemechanics.pro/content/knowledge/en/mechanic/phone-flashlight--family-multiplayer.md","aliases":["Cooperation and light communication"],"tags":["Phone flashlight interactions","Mechanics catalog"],"sourceIds":["source-47f6341cc0c6a2ab"],"sources":[{"id":"source-47f6341cc0c6a2ab","title":"Morse-It","url":"https://apps.apple.com/us/app/morse-it/id284942940?uo=4","verifiedAt":null}],"sections":[{"id":"principle","title":"How it works","body":"Several sources, an observer or a separate light receiver appear."},{"id":"variants","title":"Variants","body":"### Variants and applications\n\n<a id=\"family-multiplayer-variants\"></a>\n\n- Sender and observer. Action: One transmits light, the second reads and acts. Application: Asymmetrical quest, communication through a room window, code training. Requirements: Rear LED and control from the application; Multiple devices/participants; sometimes an observer is enough. Conditions: The recipient can be a person; automatic communication requires a camera or photosensor. <a id=\"variant-91\"></a>\n- Light response-confirmation. Action: The second participant responds after receiving the message. Application: Ping test, shared password, challenge-response sequence. Requirements: Rear LED and app control; Multiple devices/participants; sometimes an observer is enough. Conditions: Devices can exchange data over the network; then light is an interface, not a transmission channel. <a id=\"variant-92\"></a>\n- Message relay. Action: Everyone receives a drawing and passes it on. Application: Command memory, light “damaged phone”, chain of rooms. Requirements: Rear LED and control from the application; Multiple devices/participants; sometimes an observer is enough. Conditions: Reading errors become part of the game if explicitly stated in the rules. <a id=\"variant-93\"></a>\n- Synchronous activation. Action: Multiple players turn on the lights in an agreed window. Application: Open a shared virtual lock, team rhythm. Requirements: Rear LED and app control; Multiple devices/participants; sometimes an observer is enough; Software game rule. Conditions: For an accurate estimate, use synchronized game clocks and latency tolerances. <a id=\"variant-94\"></a>\n- Alternation of sources. Action: Players maintain lighting in turns without long pauses. Application: Role transfer, object tracking, general temporary bridge. Requirements: Rear LED and control from the application; Multiple devices/participants; sometimes an observer is enough; Software game rule. Conditions: The program can evaluate teams; continuous real light checks external receiver. <a id=\"variant-95\"></a>\n- Several directions at the same time. Action: Sources illuminate different sides of the same scene. Application: Shadow puzzle, cooperative review, several virtual switches. Requirements: Rear LED and app control; Multiple devices/participants; sometimes an observer is enough; Prepared props or external sensor. Conditions: Design the real scene taking into account wide beams and mutual illumination. <a id=\"variant-96\"></a>\n- Separated information. Action: One has a map or instructions, the other has a flashlight. Application: “Mineweeper” with a voice navigator, quest with a scout. Requirements: Rear LED and control from the application; Multiple devices/participants; sometimes an observer is enough; Software game rule. Conditions: Light gives an executive role; It is not necessary to recognize it by the camera for communication. <a id=\"variant-97\"></a>\n- Finding the owner of the signal. Action: Match the visible picture with a given participant. Application: Search for a pair, acquaintance in a group, distribution of teams. Requirements: Rear LED and control from the application; Multiple devices/participants; sometimes an observer is enough. Conditions: This is a game ID that can be copied; he doesn't provide identification... <a id=\"variant-98\"></a>\n- Channel blocking. Action: Place an obstacle between the source and receiver according to the rules. Application: Tabletop protection of the beacon, competition for line of sight. Requirements: Rear LED and control from the application; Multiple devices/participants; sometimes an observer is enough; Prepared props or external sensor. Conditions: An observer or sensor is required; Do not use the blinding of someone else's camera or person as a target. <a id=\"variant-99\"></a>\n- Physical props management. Action: Shine on a photo sensor that turns on a separate device. Application: Quest castle, toy robot, interactive model. Requirements: Rear LED and app control; Prepared props or external sensor. Conditions: You need an external photosensor, controller and threshold taking into account external light. <a id=\"variant-100\"></a>"},{"id":"context","title":"Context and limits","body":"Author's working classification for designing games and interactions. Options can overlap and combine; the list is not a generally accepted standard or proven exhaustive list. Application examples are conditional unless a specific verifiable observation is indicated nearby. Sources support individual techniques and technical limitations."}],"relations":[],"placements":[{"catalogId":"phone-flashlight","id":"family-multiplayer","title":"Phone flashlight interactions","url":"https://gamemechanics.pro/en/mechanics/phone-flashlight/#family-multiplayer","categoryIds":["section-1"]}],"supersededBy":[],"attributes":{"preview":{"updatedAt":"2026-10-22","title":"Cooperation and light communication","description":"Light carries a signal to another participant. Morse-It encodes text as flashes for a person in line of sight; automatic reception is not implied.","image":{"src":"images/mechanics/flash-morse-encode.webp","width":720,"height":1280,"crop":{"x":0,"y":50,"width":720,"height":650},"game":"Morse-It","sourceUrl":"https://apps.apple.com/us/app/morse-it/id284942940?uo=4","originalUrl":"https://is1-ssl.mzstatic.com/image/thumb/PurpleSource126/v4/e7/81/95/e7819588-ed18-f189-d310-f9fe38042879/f80c3936-c8ce-4640-bd6a-fd6ad5b820d8_5_-_5.5_-_iPhone_8_Plus-1.png/720x1560bb.jpg","credit":"Francis Bonnin","rights":"© Francis Bonnin. Developer-distributed App Store screenshot. All rights reserved; excluded from MIT and CC BY 4.0.","caption":"Morse-It: encoding text as a light-signal sequence","alt":"Morse-It: encoding text as a light-signal sequence","markers":[{"x":50,"y":22,"label":"Two dots and a dash represent the current light-code symbol"}]},"tips":["Agree on the code, visibility and acknowledgment, and provide a non-light channel."],"examples":[{"title":"Morse-It","url":"https://apps.apple.com/us/app/morse-it/id284942940?uo=4"}]}},"endsAt":null,"provenance":"Original editorial design catalog consolidated from project discussions on 2026-10-20. Complete discussion item lists and contextual limitations are preserved; linked primary sources support specific techniques, not the entire classification. English translation was prepared with machine assistance and editorial review.","license":"CC-BY-4.0","codeLicense":"MIT","attribution":"gamemechanics.pro contributors","catalogKey":"catalog/phone-flashlight"}}