The primary goal for Slay the Spire speed optimization is Action-Chain Compression. Even with Fast Mode on, the game forces a small delay after every card played to allow the animation to finish. This configuration focuses on maxing out the internal Fast Mode flags and leveraging high-refresh-rate logic to make the “Whirlwind” and “Shiv” animations happen almost instantaneously.
File Path
Slay the Spire stores its settings in .prefs files, which are actually plain-text XML/Properties files. Close the game before editing:
[Steam_Path]\steamapps\common\SlayTheSpire\preferences\STSPlayer
(Note: If you use multiple profiles, it will be STSPlayer_0, STSPlayer_1, etc.)
Technical Configuration (The 2026 “Speed-Runner” Template)
Open the file with a text editor (Notepad++ is recommended). Look for these specific keys. If they aren’t there, you can manually append them to the bottom of the list:
# Slay the Spire Fast Tweak - GameEngineer.net
FAST_MODE: "true"
UPLOAD_SETTINGS: "false"
ANIMATION_LIMIT: "true"
MUTE_IF_BG: "true"
# Manual Engine Overrides
fps_limit: "240"
vsync: "false"Parameter Breakdown:
- FAST_MODE: “true”: This is the baseline. It ensures the in-game toggle is locked to “On.”
- fps_limit: “240”: A known “quirk” of the Slay the Spire engine (LibGDX) is that certain animations—like the Whirlwind spin or Shiv throws—actually play faster at higher frame rates. Setting this to 240 (even on a 60Hz monitor) reduces the “tick” time between damage instances.
- vsync: “false”: Essential to allow the FPS limit to influence animation speed. Removing the sync eliminates the tiny “input lag” when clicking cards from your hand.
- UPLOAD_SETTINGS: “false”: Disables redundant data syncing during the run, which can occasionally cause “micro-freezes” at the start of a new floor.
Strategy for 2026 Animation Skipping
- The “Spacebar” Trick: While playing, holding the Spacebar during non-interactive sequences (like chest openings or rewards) acts as a manual “Fast-Forward” button that stacks with the config tweaks.
- SuperFastMode (Mod): In 2026, if the config tweak isn’t enough, the “SuperFastMode” mod on the Steam Workshop is the community standard. It allows you to set the animation speed to $2\times$ or $5\times$ without breaking the game’s internal logic.
- Disable Particle Effects: In the in-game “Graphics” menu, turn off Particle Effects. This is crucial for “Infinite” builds. If you are playing 50+ cards a turn, the “smoke” and “sparkle” sprites will eventually lag the UI regardless of your FPS.
- Summed Damage: Ensure “Summed Damage” is enabled in the preferences. This prevents the game from rendering 10 individual “1” damage pop-ups, instead showing a single “10,” which saves significant CPU processing during multi-hit attacks.
Key Efficiency Parameters
| Parameter | Recommended Value | Impact |
| Fast Mode | true | Baseline animation speed increase. |
| FPS Limit | 120 – 240 | Speeds up “Whirlwind” and “Multi-hit” ticks. |
| Particles | Disabled | Keeps the UI responsive during “Infinites.” |
| Summed Damage | Enabled | Reduces the number of UI elements rendered. |
Frequently Asked Questions (FAQ)
Why does high FPS make the game faster?
The game’s “DeltaTime” logic is partially tied to the render loop. At higher FPS, the “wait” cycles between damage numbers being drawn are completed faster, resulting in about a 30% speed increase at 240 FPS vs 60 FPS.
Can I get banned for using “SuperFastMode”?
No. Slay the Spire is a single-player game. In fact, most speedrun categories have specific rules allowing for Fast Mode or mods that don’t alter the RNG.
Does “Fast Mode” affect my decisions?
Technically, no. It only speeds up the visuals. However, it can make it harder to see exactly which intent an enemy is switching to if you aren’t paying close attention.
My game is flickering at 240 FPS!
If you see flickering, lower the fps_limit to 120. Some monitors cannot handle the “unsynced” frames from Slay the Spire’s older engine.
Conclusion and Expected Results
By combining the FAST_MODE flag with an uncapped FPS Limit in your STSPlayer preferences, you are removing the artificial “weight” of the card animations. You can expect faster combat transitions, snappier card plays, and a significant reduction in time-per-run, allowing you to reach the Heart in record time.