Prismath

About Prismath

Prismath, by ghandpivot, is a logic puzzle built around lasers and arithmetic. The grid has numbered and lettered entry points on all four sides. Hidden inside are keyslots whose shapes and values match the prisms in your inventory, which come in shapes such as triangles, a hexagon and a parallelogram, each carrying a number.

You pick a row or column on the border to fire a laser. The game tells you where it started and where it ended up (for example 3-C) and the total it picked up on the way: every prism it collides with adds its number to the sum. From the paths and sums together you work out where each prism must be. Then you drag the prisms from your inventory onto the grid and lock in your answer; a wrong guess costs one of your two lives.

The daily puzzle is generated from the date, so everyone playing on the same date gets the same grid, and the game saves your progress on it. Statistics track your current win streak. It plays free in the browser on itch.io, with a How to play guide built in.

It suits players who like Black Box, Minesweeper-style deduction or laser-and-mirror puzzles, and who enjoy a little arithmetic with their logic.

How to play Prismath

1. Open Prismath on itch.io; read How to play the first time.
2. Select a row or column on the grid's border to fire a laser.
3. Note where the laser comes out and the sum of the prisms it hit.
4. Use the paths and sums to deduce where each prism's keyslot is, and drag the prisms onto the grid.
5. Lock in the sequence when you are sure; a wrong answer costs one of your two lives.

Tips

• Fire lasers along the edges first: a laser that goes straight through tells you a whole line is empty.
• Compare sums: a laser that adds only one prism's value pins down which prism it hit.
• Large prisms cover several cells, so place them before the small ones.
• Do not lock in until every prism fits all the laser results; you only have two lives.

Questions