What this game is
Two motorcycles run across a grid leaving a solid wall behind them. You cannot stop and you cannot turn back. Whoever hits something first loses.
That simple setup turns out to be a surprisingly deep game. The wall you build is both your weapon and your trap: it takes space away from your opponent, and from you as well. The real fight is not about cutting the other rider off — it is about ending up in the bigger half once the field finally splits in two.
A round lasts about twenty seconds, and it is usually decided by one turn made a third of a second too early or too late.
Rules
- The playfield is a dark grid. You ride the blue cycle, the computer the red one. Both start in the middle and immediately head upwards.
- The cycles move on their own, one cell per tick, about fourteen cells a second. You cannot brake and you cannot stop.
- Steer with the arrow keys or WASD; on a touch screen, swipe across the field. You may only turn left or right — a 180° reversal is ignored.
- Every cell you pass through becomes a wall and stays one until the round ends. Your own trail is exactly as lethal to you as your opponent's.
- You lose the round by driving into the border, into your own trail or into the opponent's.
- If both crash on the same tick — head-on collisions included — the round is a draw and gets replayed, and the score does not change.
- The match goes to the first player to win five rounds. It is the match, not the individual round, that is counted in the strip below the field.
- Each round opens with a one-second "Ready" pause. You can already steer during it; the turn is remembered.
How to play better
- Do not rush to cut your opponent off in the first seconds. While the field is open, cutting in gains almost nothing and costs you your own freedom to manoeuvre.
- Stay close to walls — the border and your own trail. Running tight along an obstacle wastes far fewer free cells than sweeping loops across open ground.
- Watch who is sealing whom in. The moment the field splits into two parts, the winner is whoever has more free cells in his own part, no matter who rode more elegantly.
- After the split the game becomes a solitaire puzzle: fill your half in tight rows, the way a lawn gets mowed. Every cell you skip is one tick of life thrown away.
- In a head-on approach, do not be the first to turn. Whoever swerves early has just handed over both the passage and the space behind it.
- Think one turn ahead, not three. A tick is seventy milliseconds; what usually kills you is not a bad plan but an arrow key pressed a moment late.
A bit of history
Disney released the film Tron in 1982 — a programmer pulled inside a computer. What audiences remembered best was the motorcycle scene: two riders on a glowing grid, each leaving a wall behind him, only one meant to survive.
The same year Bally Midway put out the Tron arcade cabinet based on the film, four minigames in one, and one of them was the light cycle race. The machine did better business than the film did on its initial release.
After that the scene outgrew the film. Clones appeared on the BBC Micro, the Oric and the ZX Spectrum, and in the early 2000s Armagetron Advanced turned the same duel into a 3D multiplayer game. The light cycle duel became a genre of its own, considerably more durable than the movie that started it.
This version is built after the applet that ran on this site from 2005 and keeps its look: the cyan panel, the old-fashioned menu bar and a match played to five wins.
About the levels
All three share one thing: the computer decides afresh on every tick and only ever picks between three options — straight, left, right. If at least one of them is safe, no level will drive into a wall.
Easy keeps going straight in 85 cases out of 100, turns at random once in twenty, and when it does run out of room turns towards whichever neighbouring cell has more free neighbours of its own. That is exactly one cell of vision. It drives into dead ends readily and often.
Hard measures, for each of the three options, how many free cells lie straight ahead — but no further than twelve — and takes the longest one. One time in ten it picks at random among the options that score close to the best, so as not to be predictable. It only sees a straight ray: a long corridor ending in a dead wall looks wonderful to it.
Expert flood-fills the free area it would end up inside after each option — up to six hundred cells — and takes the largest. When the areas come out close it hugs walls, and it avoids a cell right next to your head so as not to catch a head-on. That is why it has a decent feel for who has trapped whom. Its blind spots are real too: the flood fill is a snapshot of this instant and knows nothing of the walls you are about to build, and it cannot tell two areas apart once both are over six hundred cells — so early in an open round every direction looks the same to it.