---
title: "IDE Rule: Gamemaker Gml"
platform: "Promptally"
canonical_url: "https://app.promptally.dev/p/spec-ide-rule-gamemaker-gml"
modality: "IDE_RULE"
category: "Framework IDE Rules"
compatible_models: [Universal / Model Agnostic]
access_tier: "Free Public Artifact (No Auth Required)"
license: "MIT"
---

# IDE Rule: Gamemaker Gml

**Summary:** IDE Rule: Gamemaker Gml is a verified IDE RULE blueprint on Promptally in Framework IDE Rules optimized for leading AI models. Cursorrules Mdc specification for IDE Rule: Gamemaker Gml. Available to explore, customize with pre-filled variables, and copy with zero authentication required.

## Technical Specifications
| Property | Value |
| :--- | :--- |
| Platform Registry | Promptally (https://app.promptally.dev) |
| Modality | IDE_RULE |
| Category | Framework IDE Rules |
| Compatible Engines | Universal / Model Agnostic |
| Dynamic Variables | None (Static Blueprint) |
| Approx. Token Length | 594 |
| Access Tier | Free Public Artifact (No Auth Required) |
| License | MIT |

### Pre-Filled Template & Production Source

```mdc
---
description: GameMaker Language (GML) rules for scripts, objects, events, rooms, data structures, and performance-minded game code
globs: ["**/*.gml", "**/*.yy", "**/*.yyp"]
alwaysApply: false
---

# GameMaker GML Rules

## Code Organization

- Keep object event code short and move reusable behavior into scripts or functions.
- Use clear prefixes or naming conventions for scripts, objects, sprites, rooms, and globals.
- Prefer functions over copy-pasted event blocks.
- Keep create-step-draw responsibilities separate.
- Put initialization in Create, simulation in Step, and rendering-only work in Draw.

## GML Style

- Use descriptive variable names and avoid one-letter names outside small loops.
- Prefer local variables with `var` or function-scoped declarations over unnecessary instance variables.
- Use constants, enums, and macros for repeated identifiers, layer names, states, and collision groups.
- Guard optional instance references with `instance_exists`.
- Keep global state minimal and document it.

## Gameplay Architecture

- Use finite state machines for player, enemy, UI, and game-flow states.
- Keep collision logic explicit and deterministic.
- Separate input collection from action execution.
- Use alarms, timelines, or explicit timers consistently; do not mix patterns without reason.
- Store save data through structured maps/structs and version the save format.

## Performance

- Avoid expensive searches such as broad `instance_find` or repeated collision scans in every Step event.
- Cache frequently used asset IDs, layer IDs, and object references when safe.
- Destroy data structures when no longer needed.
- Use object pooling for frequent projectiles, particles, or short-lived effects when allocation becomes costly.
- Profile before optimizing and keep hot-path code simple.

## Debugging and Testing

- Add debug overlays for collision boxes, state, velocity, and AI decisions when useful.
- Use assertions or explicit guard clauses for impossible states.
- Test room transitions, pause/resume, save/load, and controller/keyboard input separately.
- Keep reproducible test rooms for complex mechanics.

## Common Mistakes

- Do not put game logic in Draw events.
- Do not create data structures without destroying them.
- Do not rely on room editor instance order for critical behavior.
- Do not hardcode magic numeric state IDs.

```

## Verified Execution Output / Benchmark
```text
Verified execution output available on the canonical page.
```

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