How do I know if my game has a Steam Deck problem?

Look for problems on the Deck specifically, especially ones that don't happen on Windows. The defining sign is crashes on the Steam Deck but not on Windows (the game working on Windows but crashing on the Deck, since the Deck runs Windows games through Proton on Linux, the Proton/Linux layer can cause crashes that don't happen natively). A sign is problems with controller input or the Deck's screen (the game not handling the Deck's controller well, or UI not readable at its screen size, since the Deck is a handheld). And a sign is performance issues on the Deck's constrained hardware (the game running poorly on the Deck while fine on desktop). To diagnose, capture crashes and performance with device context from the field (identifying the Steam Deck), and consider the Deck's specific environment. If your game crashes on the Deck but not Windows, has controller/screen problems, or performs poorly on the Deck, you have a Steam Deck problem. The Deck is a specific environment: Linux-based, running Windows games through the Proton compatibility layer (which can surface crashes that don't happen natively on Windows), a handheld with controller input and a small screen (so keyboard/mouse-built games and small-text UIs have problems), and constrained hardware with a power budget (so performance can suffer). These Deck-specific factors cause problems your Windows testing won't reveal, since the Deck's environment (Proton/Linux, handheld, constrained hardware) differs from Windows. So you know your game has a Steam Deck problem from the Deck-specific signs: crashes on the Deck not Windows (Proton/Linux), controller/screen problems (handheld), performance issues (constrained hardware), all of which are largely invisible from Windows testing (the Deck's environment is different) and require testing on the actual Deck or capturing crashes from Deck players to see. Capturing crashes with device context from the field is how you see Deck-specific crashes (especially if you don't have a Deck to test), the Deck clustering reveals them, and the fact that they're on the Deck (and not Windows) points at the Deck's environment (Proton/Linux) as the cause.

Why does my game crash on the Steam Deck but not on Windows?

Because the Deck is a specific environment quite different from a typical Windows desktop: it runs a Linux-based OS, Windows games run through the Proton compatibility layer rather than natively, and it's a constrained handheld with controller input, each of which can cause crashes your Windows testing won't reveal. Proton, in particular, can surface crashes or quirks that never appear when the game runs natively on Windows, since it's translating between the Windows game and the Linux system, edge cases in that translation can crash a game that's perfectly stable on Windows. The Deck's constrained hardware (weaker than a desktop, with a power and thermal budget) can also cause resource-related crashes or problems a powerful desktop doesn't. And its handheld input model (controller, small screen) can break assumptions a keyboard-and-mouse game makes. So your game crashes on the Steam Deck but not on Windows because the Deck's environment (Linux + Proton + constrained handheld hardware) differs from Windows in ways the game hits, most often a Proton-layer issue (the translation between the Windows game and Linux causing a crash that doesn't happen natively on Windows), but also potentially the constrained hardware or handheld input. This is why Deck-specific issues are largely invisible from Windows testing: the Deck-specific problems (especially Proton-layer crashes) are structurally invisible when running natively on Windows, since the Proton/Linux environment that causes them isn't present. To find and fix Deck crashes, capture crashes from Deck players (with device context, so you can see when crashes are concentrated on the Steam Deck, since the Proton/Linux layer can crash games that work on Windows) and test on actual Deck hardware (to see how the game behaves under Proton on the Deck). The fix addresses the Deck-specific cause (handle the Proton-layer issue, the constrained hardware, the handheld input). So your game crashes on the Steam Deck but not Windows because the Deck's specific environment (Linux/Proton especially, plus constrained hardware and handheld input) causes problems that don't occur when running natively on Windows, and diagnosing it requires capturing crashes from Deck players (the Deck clustering revealing the Deck-specific crashes) and testing on the actual Deck (to see the Proton/Linux behavior), then addressing the Deck-specific cause. Capturing crashes from Deck players with device context is especially important because the Deck's Proton/Linux environment can produce crashes that no amount of Windows testing reveals, so without a Deck to test, field crash capture from Deck players is how you see the Deck-specific crashes.

How do I fix Steam Deck problems?

Test on actual Deck hardware, capture crashes from Deck players, and address the Deck-specific causes (Proton/Linux, constrained hardware, handheld input). Test on actual Steam Deck hardware: since the Deck's environment (Linux, Proton, constrained handheld hardware) differs from Windows and produces problems your Windows testing won't reveal, testing on a real Deck is the most reliable way to see how the game behaves under Proton on the Deck and catch Deck-specific issues (Proton crashes, performance, controller/screen problems). Capture crashes from Deck players: since you likely can't test every Deck scenario (and may not have a Deck), capture crashes from real Deck players with device context, so you can see when crashes are concentrated on the Steam Deck (the Deck clustering revealing Deck-specific crashes the Proton/Linux layer causes), with the context to diagnose them, this is essential because the Deck's Proton/Linux environment can crash games that work on Windows, invisible without capturing from Deck players. Then address the Deck-specific causes: for Proton/Linux crashes (the most common Deck-specific issue, crashes that don't happen natively on Windows), investigate the Proton-layer issue and fix it (often a compatibility issue in how the game runs under Proton). For controller/screen problems (the handheld nature), ensure proper controller support (the Deck uses controller-style input, so a keyboard/mouse game needs controller handling) and readable UI at the Deck's screen size. For performance issues (the constrained hardware), optimize for the Deck's hardware (it's weaker than a desktop with a power budget, so the game may need to run within those limits). Verify fixes on the Deck or in the field from Deck players (the problems stopping on the Deck). So you fix Steam Deck problems by testing on actual Deck hardware (to see and catch the Deck-specific issues), capturing crashes from Deck players (to surface the Deck-specific crashes, especially Proton/Linux ones, you can't reproduce on Windows, with the device context revealing the Deck clustering), and addressing the Deck-specific causes (Proton/Linux compatibility for the crashes, controller/screen handling for the handheld nature, optimization for the constrained hardware). The key is that Deck problems come from the Deck's specific environment (Linux/Proton, handheld, constrained hardware) that differs from Windows, so they're largely invisible from Windows testing and require testing on the actual Deck (to see them) plus capturing crashes from Deck players (to surface the Proton/Linux crashes you can't reproduce on Windows), then addressing the Deck-specific causes. Capturing crashes from Deck players with device context is especially valuable, it's how you see the Deck-specific crashes (the Deck clustering) the Proton/Linux environment causes, which Windows testing won't reveal, so you can fix the Deck problems even for scenarios you didn't test (or without a Deck), supporting the Deck well (which affects your compatibility rating, reviews, and sales to the large Deck audience).

Signs Your Game Has a Steam Deck Problem

Quick answer: Watch for crashes on the Deck but not Windows, controller input or screen problems, performance issues on the Deck's hardware, and Deck complaints you can't reproduce. The Deck's Linux/Proton environment causes problems Windows testing won't reveal.

The Steam Deck is a specific environment, Linux-based, running Windows games through Proton, handheld, that can cause problems your Windows testing won't reveal. Here are the signs your game has a Steam Deck problem.

Crashes on the Deck but Not on Windows

The defining sign is crashes on the Steam Deck but not on Windows, the game working on Windows but crashing on the Deck. Since the Deck runs Windows games through Proton on Linux, the Proton/Linux layer can cause crashes that don't happen natively on Windows, so Deck-only crashes are a Deck-specific problem.

Bugnet captures crashes with device context, so Deck-specific crashes are identifiable. Crashes on the Deck but not Windows are the defining sign of a Steam Deck problem, and capturing crashes with device context (identifying the Steam Deck) is what reveals it, the Proton/Linux layer can crash games that work on Windows, so Deck-only crashes (visible by the Deck clustering) point at the Deck's specific environment as the cause.

Controller Input or Screen Problems

A sign is problems with controller input or the Deck's screen, the game built for keyboard/mouse not handling the Deck's controller well, or UI not readable at the Deck's screen size. Since the Deck is a handheld with controller input and a small screen, input/UI problems specific to it are a Deck problem.

Bugnet captures issues with device context, so Deck input/UI problems are identifiable. Controller input or screen problems are a sign of a Steam Deck problem (the Deck's handheld nature, controller input, small screen), and capturing the issues with device context (on the Deck) helps you identify them, pointing at handling the Deck's controller input and ensuring the UI is readable at its screen size to fix the Deck input/UI problems.

Performance Issues on the Deck's Constrained Hardware

A sign is performance issues on the Deck, the game running poorly on the Deck's constrained handheld hardware (which is weaker than a desktop). If the game performs poorly on the Deck (frame drops, stutters) while fine on desktop, the Deck's constrained hardware is the cause, a Deck performance problem.

Bugnet captures performance and device context, so Deck performance issues are identifiable. Performance issues on the Deck's constrained hardware are a sign of a Steam Deck problem, and capturing performance with device context (on the Deck) reveals it, the Deck's hardware is constrained (weaker than desktop, with a power budget), so a game that's fine on desktop can perform poorly on the Deck, pointing at optimizing for the Deck's hardware.

Watch for crashes on the Deck but not Windows, controller input or screen problems, performance issues on the Deck's hardware, and Deck complaints you can't reproduce. The Deck's Linux/Proton environment causes problems Windows testing won't reveal.