A reflection puzzle with a visible goal
A mirror puzzle game turns a familiar rule into a routing problem: light reflects from a surface at the same angle at which it arrives, measured from the surface normal. A useful turn depends on both the incoming beam and the mirror’s orientation. Two mirrors at the same angle can send light in different directions if the light reaches them from different sides.
The challenge above gives that rule a concrete job. The lamp, two mirrors and gate A stay in fixed positions. Turn the mirrors until the beam passes through the opening in the stone wall. The table reports the light actually reaching the gate; touching the frame or seeing a bright glow nearby is not enough.
How to plan a mirror route
Start by identifying the next useful destination for the beam. Here, Mirror 1 needs to illuminate Mirror 2 before the gate can receive anything. Make that first section work, then adjust the second reflection. Changing both angles at once makes it harder to see which adjustment helped.
It also helps to look backward from the gate. Which opening can light pass through to reach it? Which mirror can send light through that opening? Working from both ends reduces the number of possible routes you need to consider. In the larger chambers, this is especially useful when a wall hides the most direct path.
Moving a mirror and rotating it solve different problems
This practice keeps positions fixed so you can concentrate on reflection. In the full game, you can move as well as rotate an instrument. Moving a mirror determines which part of a beam it catches; rotation determines where the intercepted light goes next. If the mirror misses the beam completely, changing its angle alone may not help.
The mirrors also have finite length. A wide beam can partly miss a mirror or be clipped by the edge of a passage. That is why Prism Riddle checks received energy as well as direction. A route that carries only a sliver of light may need better placement or a lens, rather than one more turn.
Why a small turn can make a large difference
For a fixed incoming direction, rotating a flat mirror changes the reflected direction by twice the mirror’s rotation angle, as long as the beam still meets the same surface. Over a long distance, a small angular change can move the light well past a narrow target. Use the degree field or your keyboard’s arrow keys in the field when a slider feels too coarse.
The angle shown by the controls is the mirror’s placement angle in the drawing. It is not the angle of incidence. The latter is measured between the incoming ray and the perpendicular to the mirror. Keeping these two meanings separate helps explain why simply typing the direction of the target does not necessarily aim the beam at it.
From laser reflection puzzles to a full optical toolkit
If you enjoy laser and mirror puzzles, this is the same kind of visible beam-routing problem: connect a source to a receiver through a sequence of reflections. Prism Riddle extends that idea with finite-width light, multiple wavelengths, lenses, prisms, splitters and targets that sometimes need to remain dark.
A mirror preserves the beam’s wavelengths in the game’s ideal reflection model. A prism puzzle changes the problem by sending different wavelengths along different directions. A splitter shares the incoming energy between branches. Combining those tools lets one chamber ask for several colored gates at once.
This is a geometric-optics puzzle, not a complete laboratory laser simulation. The free lab includes additional stated models for polarization and diffraction orders; it does not simulate coherent interference between independent beam paths.
Play the full light bending puzzle game
The practice above is free and separate from the campaign. Prism Riddle has 80 formal chambers, with the first three available without payment. The first formal chamber combines five instruments and several route decisions, so the small mirror exercise gives you a way to learn the controls before taking on that challenge.
Open the first free chamber to move and rotate the full set of instruments. Free route hints, undo, fullscreen play and precise controls are available. Purchased access unlocks chambers four through eighty; exact walkthroughs are optional. The practice does not consume a walkthrough credit or add a campaign completion to your record.
For the complete solving workflow, read how to play Prism Riddle. Use “Experiment with these optics in Free lab” above to copy the lamp, mirrors and gate into an open workspace. You can change their positions and settings there; the fixed wall belongs to this page’s challenge.