How to make a roguelike with AI

Ask for a generated dungeon, short runs and a death screen, and insist that every random choice comes from one seeded generator rather than from Math.random. That single constraint is what makes the genre workable with a model. Without it, half of what goes wrong happened once and can never be shown to anybody again.

Four steps to a run you can play twice#

Build a small roguelike as ONE self-contained .html file. No
frameworks and no images. Draw the dungeon on a canvas with shapes.

SEED: write a tiny seeded random number generator and route every
random choice in the game through it. Math.random must not appear
anywhere. One run uses one generator, built from one integer seed.

START SCREEN: a play button and a text box where a seed can be typed.
Left empty, take a seed from the clock and display it.

GENERATION: rooms joined by corridors on a grid, laid out with the
seeded generator. Every room reachable from the start. A stairway down
placed somewhere other than the room the player begins in.

THE RUN: five floors, each slightly larger and more dangerous than
the one above it. A whole run should be over quickly, win or lose.

MOVEMENT: arrow keys or WASD move one tile. Enemies move only when
the player does, so nothing happens while the player is thinking.

ENEMIES: two kinds. One chases across the floor. One guards a room
and hits harder. Both placed by the seeded generator.

ITEMS: health, and one item that changes how fighting works. Placed
by the seeded generator, so one seed always gives the same items in
the same rooms.

DEATH SCREEN: say what killed the player, on which floor, after how
many turns. Show the seed in large type, with a button that copies it
and a button that replays that exact seed.

PHONE: a swipe moves one tile in that direction. Include
canvas { touch-action: none; } so swiping never scrolls the page.

Animate the steps and the damage flashes from the seconds that
elapsed since the previous frame, clamped so it can never pass 0.05.
Keep floor count, room sizes, enemy counts, damage and starting
health in one CONFIG object at the top, each with a comment.

What a seeded generator actually buys you#

The usual way this goes wrong is quiet. You play, something absurd happens, you reload to look at it properly, and it is gone. The next twenty runs behave. You cannot describe the fault precisely, so you describe it loosely, and a loose description gets a loose fix that may not touch the real cause.

A seeded generator removes the guessing. The generator is a function of one integer, so the same integer produces the same sequence, which produces the same dungeon. Paste the seed into a message with the thing that went wrong and the model is working from the same floor you were.

// A small seeded generator. Same seed in, same sequence out.
function rng(seed) {
  let a = seed >>> 0;
  return function () {
    a = (a + 0x6D2B79F5) >>> 0;
    let t = Math.imul(a ^ (a >>> 15), 1 | a);
    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
  };
}

// One per run, built from whatever the start screen supplied.
const seed = Number(seedBox.value) || (Date.now() % 1e9);
const rand = rng(seed);

// Everywhere else in the game, rand() replaces Math.random().
const roomWidth = CONFIG.minRoom + Math.floor(rand() * CONFIG.roomSpread);

It also buys you something the player can use. Two people can compare the same dungeon, which turns a score into a fair comparison rather than a report of how lucky somebody was. Posting a hard seed and daring other people to clear it is a genuine reason to come back.

Run length, and what survives a death#

A run has to be short enough that losing it is annoying rather than painful. If a death costs an hour, players stop taking risks, and a roguelike with careful players is a slow one. Short runs let people experiment, and experimenting is where the genre gets its replay value.

The distinction worth holding is between knowledge and advantage. Learning that the guard enemy cannot follow you through a corridor is progress and it costs nothing. Starting the next run with saved gold is advantage, and it eats the tension the whole design runs on.

Adding to the pool is the one safe form of unlocked content. Find a strange item once and it becomes something later runs might offer. The player gains variety rather than strength, so the game is wider than it was yesterday and no easier.

A death screen that says what killed you#

Most first builds print the word dead and a score. That is the biggest wasted moment in the genre. Death is the one point where the player is paying full attention to what just happened, and wondering whether any of it was their own fault.

• Name the cause. Not died. Killed by the guard on floor three, with two health left, after eighty one turns. The player either accepts that or argues with it, and both mean they are still engaged.
• Show the seed large. It is the one thing on the screen you want copied. Put a copy button next to it and a replay button under it.
• Offer the same seed again. A player who nearly cleared a floor wants that floor, not a new one. This is also how you test a fix in seconds.
• Keep the best run visible. Depth reached and turns taken. It is the only scoreboard the genre needs and it costs two lines of storage.

Causes of death are also your best source of balance information. If every death screen names the same enemy, that enemy is doing the work of the entire game. If one is never mentioned, it is not a threat and the floor would read the same without it.

💀Roguelikes written by AI

‹ ›

Opus 5.5

★ 5.0100 plays👑 12

▶

ARCLIGHT

Fable 5.1

205 plays👑 31

▶

FROM ZERO

Sonnet 5.5

46 plays👑 9

▶

TETHER

GPT-6 Sol

57 plays👑 7

▶

RIFTWAKE

GPT-6.1 Sol

46 plays

▶

Afterlight

Common questions#

Where to go next#

When a run is one you want to beat, put it up. It gets a page recording the model and the prompt behind it, and a leaderboard where somebody else will take your best depth.

The general method is in how to make a game with AI. If you want a party and a world that persist instead, the RPG guide has the build order for that. Wording for common faults sits in the prompt guide, and the roguelikes here are worth a death or two first.