How to fix error driver-irql-not-less-or-equal in Slay the Spire

Solution Steps

1. 1 Launch your game platform (Steam, Epic Games, or Battle.net). Right-click Slay the Spire → Properties → Local Files / Installed Files → Verify integrity of game files. This checks every game file against the official version and replaces any corrupted or missing files — the #1 cause of random crashes.
2. 2 Press Windows key + X and select Device Manager. Expand 'Display adapters', right-click your GPU → Update driver → Browse my computer → Let me pick → select the latest driver. Slay the Spire is sensitive to GPU driver versions — even a slightly outdated driver can cause crashes.
3. 3 Open Windows Settings (Windows key + I) → System → Display → Graphics. Find Slay the Spire.exe in the list (or add it), click Options, and select 'High Performance'. This forces Windows to use your dedicated GPU instead of integrated graphics — a common cause of crashes in Slay the Spire.
4. 4 Press Ctrl+Shift+Esc to open Task Manager. Go to the Startup tab and disable unnecessary programs. Background apps consume RAM and CPU that Slay the Spire needs. Every background process increases crash risk.
5. 5 Open your game launcher settings. For Steam: Steam → Settings → In Game → uncheck 'Enable Steam Overlay'. For Discord: User Settings → Game Overlay → toggle off. For GeForce Experience: Settings → General → In-Game Overlay → toggle off. Overlays inject into Slay the Spire and are a leading cause of crashes.
6. 6 Press Windows key + R, type '%TEMP%' and press Enter. Delete everything in this folder (skip files in use). Then type 'prefetch' in Run and delete those too. Temporary file corruption can cause Slay the Spire to crash during asset loading.
7. 7 Download and install the latest Visual C++ Redistributables from Microsoft's official website — both x64 AND x86 versions. Slay the Spire depends on these runtime libraries. Missing or corrupted VC++ runtimes cause silent crashes to desktop.
8. 8 Check Slay the Spire crash logs. Navigate to %LOCALAPPDATA%\SlaytheSpire\Saved\Crashes (or similar). Open the latest .log file in Notepad. Look for lines containing 'Error', 'Fatal', or 'Exception' near the end — they tell you exactly what caused the crash.