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Lizely

Mirror Reflection Puzzle

Route a ray through five handcrafted mirror grids using slash and backslash tiles.

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How to use

  1. 1.Select a grid cell, then place a / or backslash mirror by tapping the cell, using the orientation buttons, or pressing the matching key.
  2. 2.Choose Trace ray or press Enter and inspect the highlighted cell-by-cell route; adjust the mirrors if it loops or exits through the wrong edge.
  3. 3.Guide each of the five signals through the exact OUT edge before a second distinct failed layout to earn exactly 1,000 points.

About Mirror Reflection Puzzle

Mirror Reflection Puzzle is a compact routing game about predicting how a ray changes direction. Each level begins with a five-by-five board, a marked entry, and one required exit. Your job is to place forward-slash and backslash mirrors in the cells, then trace the ray. Empty cells let the ray continue straight. A mirror turns it by ninety degrees according to its diagonal orientation. Reach the exact OUT edge to clear a level. The five fixed boards gradually move from a single turn to a four-mirror route, so every new signal asks you to hold a slightly longer path in mind without adding random layouts or hidden rules.

The board is fully interactive with a mouse, touch screen, or keyboard. Click or tap a cell to cycle it from empty to slash, backslash, and empty again. Keyboard players can move the selected cell with the arrow keys, type a slash or backslash to place that mirror, press 0 to clear, and press Enter to trace. Every cell is a large button with an accessible label. After a trace, visited cells display the outgoing direction, making a failed route inspectable instead of merely reporting that it was wrong. The status panel also distinguishes a ray that leaves through the wrong edge from one that enters a loop.

Scoring is deliberately transparent. Every solved level awards exactly 200 points, and all five levels produce a perfect score of 1,000. A wrong trace counts only when the current mirror layout is distinct. Checking the same failed layout again does not consume another attempt. A second different failed layout ends the run, while Restart restores level one, an empty placement map, zero mistakes, and zero points. Completed and failed states are frozen, so extra clicks or key presses cannot alter the recorded result. No account, download, upload, or server calculation is involved; the entire board and trace reducer run locally in the browser.

The ray model is intentionally narrow. It is a discrete puzzle representation using four cardinal travel directions and ideal diagonal mirrors. The direction rule follows the familiar law of reflection: the angle of reflection equals the angle of incidence when both are measured from the surface normal. In this grid, a forty-five-degree slash converts right to up, up to right, left to down, and down to left. A backslash supplies the complementary four turns. The tracer records the cell, incoming direction, outgoing direction, and mirror for each step. It stops at the target, at a different board edge, or when the same cell and incoming direction would repeat. That repeated-state check prevents an enclosed mirror route from running forever.

This is not a precision optics simulator. It does not model mirror thickness, wavelength, refraction, scattering, brightness, polarization, imperfect surfaces, or real measurements. The five levels are original game fixtures rather than copied textbook diagrams. OpenStax and The Physics Classroom are cited only for the equal-angle reflection rule that anchors the direction mapping. The exact board coordinates, entry points, exit targets, failure policy, and score belong to this game. Independent tests verify all eight incoming-direction and mirror combinations with a vector oracle, then replay literal winning paths for every level. Separate probes prove both wrong-edge termination and loop detection.

A useful solving method is to work backward from OUT. Ask which direction the ray must have in the target cell, then choose the final mirror orientation that could create it. Continue backward until the route meets the entry path. On longer levels, place only the turns you can justify and trace early; the highlighted path will show the first place your prediction diverged. Mirrors outside the active path do not affect the ray, but keeping the board sparse makes the intended route easier to audit. Because the layouts never shuffle, Restart is also useful for learning a route cleanly after an experimental run.

The interface uses the shared Lizely GameShell, including score display, best-score storage in local browser storage, Restart, keyboard help, and the double-Escape boss key. Best score is optional local convenience data and the live run remains usable if browser storage is unavailable. There are no timers, random seeds, network calls, third-party images, or paid features. The result is a small, deterministic reflection puzzle whose visible trace, fixed rules, and exact score can all be checked directly.

Methodology & sources

A pure reducer stores a 5-by-5 mirror map and traces from the authored entry one cell at a time. Slash and backslash turns use the eight equal-angle cardinal mappings documented in the evidence fixture. The tracer terminates on an exact target exit, any other boundary exit, or a repeated cell-plus-incoming-direction state. Five literal solution routes are independently replayed in tests. Correct routes add 200 and clear the next board; wrong signatures combine level and sorted placements for deduplication, and the second distinct signature deadlocks. Invalid coordinates, invalid mirror values, repeated layouts, and terminal actions preserve state.

Frequently asked questions

How do slash and backslash mirrors turn the ray?
A slash maps right to up, up to right, left to down, and down to left. A backslash maps right to down, down to right, left to up, and up to left.
What happens if the ray enters a loop?
The tracer stops when the same cell and incoming direction would repeat, labels the outcome as a loop, and lets you change the layout unless it was your second distinct miss.
Is this a full physics or optics simulator?
No. It is a deterministic grid puzzle using ideal cardinal rays and 45-degree mirrors; it does not model materials, wavelength, refraction, intensity, or physical measurements.

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