How to Write Good Bug Reports for Game Development

Learning how to write good bug reports for game development is a common challenge for game developers. A bug report that says “the game crashed” tells the developer nothing. A bug report that says “the game crashes when opening the inventory with a full stack of potions on the second floor of the dungeon, running build 1.4.2 on Windows 11 with an AMD GPU” tells them everything. The difference between these two reports is the difference between a bug that gets fixed in an hour and one that lingers on the backlog for months. This guide covers the anatomy of an effective bug report and how to write one that developers will actually want to read.

The Anatomy of a Bug Report

Every good bug report has the same core components, regardless of whether it is filed by a QA tester, a player, or an automated crash reporter. These components are: a title that summarizes the problem, reproduction steps that explain how to trigger it, expected behavior that clarifies what should happen, actual behavior that describes what does happen, environment information that narrows the scope, and a severity classification that helps with prioritization.

Missing any one of these components forces the developer to ask follow-up questions, which adds hours or days of round-trip delay. A complete bug report is a self-contained investigation package. The developer should be able to read it, reproduce the issue, and start working on a fix without any additional communication.

Here is what a well-structured bug report looks like when submitted through a tracking system:

## Title
Inventory — equipped weapon disappears after saving and reloading

## Reproduction Steps
1. Start a new game and complete the tutorial
2. Pick up the Iron Sword from the chest in Room 3
3. Open the inventory and equip the Iron Sword
4. Save the game using the pause menu
5. Quit to the main menu
6. Load the save file
7. Open the inventory

## Expected Behavior
The Iron Sword should appear in the equipped weapon slot.

## Actual Behavior
The equipped weapon slot is empty. The Iron Sword is no longer
in the inventory. The player character’s hand is empty in-game.

## Environment
- Game version: 1.4.2 (build 2026.03.15)
- OS: Windows 11 Pro 23H2
- GPU: AMD Radeon RX 7600
- RAM: 16 GB
- Input: Xbox controller

## Severity: Critical
Player loses items permanently. No workaround found.

## Reproduction Rate: 5/5

Notice how each section adds a specific layer of information. Nothing is ambiguous. Nothing requires guessing. The developer knows exactly what to do to see the bug for themselves.

Writing Effective Reproduction Steps

Reproduction steps are the most important part of the bug report. A bug that cannot be reproduced cannot be fixed with confidence. Even if a developer identifies suspicious code, without reproduction steps they cannot verify that their fix actually solves the problem.

The golden rule of repro steps is: start from a known state. Never begin with “while playing the game” or “at some point during the session.” Instead, start from a clean, reproducible starting point: “Start a new game,” “Load the attached save file,” or “Join a multiplayer lobby with two players.”

Each step should describe a single, specific action. Compare these two approaches:

// Bad: vague, multiple actions per step
1. Play through the first level and get to the boss
2. Die and restart
3. The bug happens

// Good: specific, one action per step
1. Start a new game on Normal difficulty
2. Proceed through Level 1 until reaching the boss room door
3. Enter the boss room (triggers the boss cutscene)
4. Allow the boss to defeat the player (do not attack)
5. Select "Retry from Checkpoint" on the death screen
6. Observe: the boss health bar shows 50% instead of 100%

For intermittent bugs — the ones that do not happen every time — include a reproduction rate. “Occurs approximately 3 out of 5 attempts” is far more useful than “sometimes happens.” It tells the developer how many tries they should expect before seeing the issue, and it hints at the underlying cause. A 3/5 rate suggests a race condition or timing issue. A 1/50 rate suggests something more exotic, like memory corruption or a specific hardware interaction.

If you found specific conditions that make the bug more or less likely, include those. “More likely to occur when the player is moving while the checkpoint loads” or “Only happens when vsync is disabled” are the kinds of observations that can cut debugging time from days to minutes.

Expected vs. Actual Behavior

This section seems simple, but it is surprisingly often omitted or poorly written. The purpose of expected vs. actual is to remove any ambiguity about whether the behavior is a bug or a feature. Game development is full of edge cases where the “correct” behavior is not obvious, and what looks like a bug to a tester might be intentional design.

Write the expected behavior as a factual statement about what the game should do, ideally referencing the design specification or a previous working version. Write the actual behavior as an objective observation of what the game does do.

// Bad: subjective and vague
Expected: The jump should work normally.
Actual: The jump feels weird.

// Good: specific and measurable
Expected: Pressing the jump button while grounded should launch
the player to a height of approximately 3 tiles, matching the
behavior in build 1.3.0.

Actual: Pressing the jump button while grounded launches the
player to a height of approximately 1.5 tiles. The player cannot
reach platforms that were previously accessible. The jump
animation plays at normal speed but the apex is visibly lower.

The second example gives the developer a precise measurement to check against, a reference build to compare with, and a description of the visual symptom. They can look at the jump force value, check the physics parameters, and identify the change that halved the jump height — all without asking a single follow-up question.

Environment Information That Actually Matters

Not all environment information is equally useful. For a single-player pixel art game, the GPU driver version probably does not matter. For a 3D game with custom shaders, it might be the key to the entire bug. Tailor the environment section to the type of game and the type of bug.

At minimum, always include the game version or build number, the operating system and version, and the input device (keyboard/mouse, specific gamepad model, touch screen). Beyond that, add information relevant to the bug category:

// For graphical bugs, include:
- GPU: NVIDIA GeForce RTX 4070
- GPU Driver: 551.86
- Resolution: 2560x1440
- Display mode: Borderless Windowed
- Graphics quality: Ultra
- VSync: Enabled
- Monitor refresh rate: 144Hz

// For performance bugs, include:
- CPU: AMD Ryzen 7 5800X
- RAM: 32 GB DDR4
- Storage: NVMe SSD (Samsung 970 EVO)
- Background applications: Discord, OBS (recording)
- FPS at time of issue: ~18 (normally ~90)
- Task Manager: CPU 45%, RAM 62%, GPU 99%

// For multiplayer/network bugs, include:
- Connection type: WiFi 5GHz
- Region: EU West
- Ping to server: ~45ms
- Number of players in session: 4
- Player role: Host / Client
- NAT type: Moderate

The goal is to help the developer answer the question: “Is this bug specific to certain hardware or configurations, or does it happen everywhere?” If five reports come in and they all have AMD GPUs, the developer knows where to look. If the reports span every GPU vendor and OS, the bug is likely in game logic rather than a platform-specific issue.

Automated bug reporting tools like Bugnet capture most of this information automatically. When the SDK is integrated, every crash report arrives with the OS, GPU, CPU, game version, and screen resolution already attached. This frees the reporter to focus on the reproduction steps and behavioral description rather than hunting down hardware specs.

Severity Classification for Games

Severity tells the development team how urgently the bug needs attention. Without it, every bug competes equally for developer time, which means critical crashes sit in the queue behind cosmetic typos. A consistent severity system keeps triage fast and ensures the worst bugs get fixed first.

Here is a four-tier severity system that works well for game development:

Critical (S1)
  // The game crashes, data is permanently lost, or player
  // progression is completely blocked with no workaround.
  // Examples:
  - Crash to desktop when entering the final boss arena
  - Save file corruption on load
  - Soft lock: player trapped in geometry with no way to escape
  - Multiplayer: server crashes when 8th player joins

High (S2)
  // A major feature is broken or significantly degraded,
  // but a workaround exists.
  // Examples:
  - Quest objective marker points to wrong location
    (workaround: follow the quest text description)
  - Controller rumble never stops after explosion
    (workaround: unplug and replug controller)
  - Audio cuts out after 30 minutes of play
    (workaround: restart the game)

Medium (S3)
  // Incorrect behavior that affects gameplay quality
  // but does not block progress or break features.
  // Examples:
  - Enemy AI gets stuck on corners in specific rooms
  - Particle effects render behind walls
  - Damage numbers display wrong value (visual only,
    actual damage is correct)

Low (S4)
  // Cosmetic issues, minor text errors, or polish
  // problems that do not affect functionality.
  // Examples:
  - Typo in loading screen tip
  - Character’s hair clips through hat during idle animation
  - Button hover highlight is 1 pixel off-center

When classifying severity, consider the impact (how many players are affected), the frequency (how often it occurs), and the workaround (whether players can get past it). A bug that crashes the game for 100% of players on a specific level is Critical regardless of how simple the fix might be. A bug that causes a minor visual artifact in a rarely visited area is Low even if the fix is complex.

Some teams add a separate priority field that reflects business urgency rather than technical severity. A Low-severity typo on the store page might have High priority because it affects purchasing decisions. Keep severity and priority as separate dimensions to avoid conflating them.

Attachments: Screenshots, Video, and Logs

A screenshot is worth a thousand words in a bug report. A video clip is worth even more, especially for bugs that involve timing, animation, or movement. Always attach visual evidence when the bug has a visible symptom.

For screenshots, capture the full game window (not a cropped section) and annotate it if the issue is not immediately obvious. Circle the problematic area or add an arrow pointing to the artifact. For video, keep it short: show the reproduction steps being performed and the bug occurring. Ten seconds of focused video is better than five minutes of wandering gameplay.

Log files are essential for crashes, performance issues, and networking bugs. Most game engines write logs to predictable locations:

# Godot log locations
# Windows: %APPDATA%\Godot\app_userdata\[Project Name]\logs\
# macOS:   ~/Library/Application Support/Godot/app_userdata/[Project Name]/logs/
# Linux:   ~/.local/share/godot/app_userdata/[Project Name]/logs/

# Unity log locations
# Windows: %APPDATA%\..\LocalLow\[Company]\[Product]\Player.log
# macOS:   ~/Library/Logs/[Company]\[Product]\Player.log
# Linux:   ~/.config/unity3d/[Company]/[Product]/Player.log

# Unreal Engine log locations
# Windows: [Project]\Saved\Logs\[Project].log
# macOS:   ~/Library/Logs/Unreal Engine/[Project]/[Project].log

When attaching logs, include the log from the session where the bug occurred, not from a clean session. If the log is very large, note the approximate timestamp of the bug so the developer can jump to the relevant section.

“The best bug report is one the developer can reproduce on the first try. Every follow-up question you eliminate is a day saved in the fix timeline.”

Related Issues

For guidance on setting up automated crash reporting that captures environment information and stack traces without player action, see our crash reporting setup guide. If you are building a public-facing bug tracker for your game community, our post on capturing and symbolicating crash dumps from player devices covers the pipeline from raw crash to readable report. For teams scaling their QA process, see our guide on building a post-launch QA pipeline.

Teach your playtesters to write bug reports like this. The twenty minutes you spend explaining the format will save hundreds of hours in back-and-forth during crunch.