About the game
Prism is a turn-based laser duel on a 7×7 board full of mirrors. Every player has a laser emitter and a glowing crystal on their own edge of the board. On your turn you flip exactly one mirror, and then every laser on the board fires at once. Each beam that leaves the board through a crystal knocks off one point of its health.
A single flip can reroute several beams, so every move is a small puzzle: send a rival's own laser back into their crystal, split a beam with a prism to hit two targets, or block the shot that is about to crack yours. Careful, your own beam can hit your own crystal too. The mirror flipped last is locked for the next player, so nobody can simply undo a move, and a live preview shows exactly where every beam will go before you commit.
Crystals have six health points. The last crystal standing wins; otherwise the healthiest crystal after ten rounds takes the match. Play against three levels of computer opponents, or pass one phone or tablet around with up to four friends.
How to play
- Your laser emitter and your crystal sit on your edge of the board.
- On your turn, flip one mirror. Then every laser on the board fires.
- Each beam that leaves the board through a crystal deals 1 damage, even if it is your own crystal.
- The mirror the previous player flipped is locked for your turn.
- Last crystal standing wins, or the most health left after 10 rounds.
Controls
- Computer
- Hover over a mirror to preview the beams and click to flip it. Arrow keys move a cursor and Space flips.
- Phone & tablet
- Tap a mirror to preview the beams, then tap the same mirror again to flip it.
Questions
Can I play Prism with friends?
Yes. Choose "Same Device" and pass the phone, tablet or computer around. Two to four people can play, and a short screen shows whose turn it is.
Why can’t I flip one of the mirrors?
The mirror with the lock icon was flipped by the previous player, so it stays locked during your turn. This stops players from simply undoing each other’s moves.
Can my own laser hurt me?
Yes. Every beam that leaves the board through a crystal deals damage, and that includes your own beam and your own crystal. Check the preview before you flip.
Is Prism free?
Yes. It runs in your browser on desktop and mobile with no download or sign-up.