Game Installation Guide

FantaTennis – Steam Deck Compatibility & Setup Guide

This entry documents the current working method for running FantaTennis on the Steam Deck.

Due to the game’s launcher, patcher, and anti‑cheat system, it cannot be launched directly through Steam, regardless of Proton version.

The procedure below outlines the reliable way to install, patch, and run the game.

Overview

FantaTennis does not natively support SteamOS or Proton.

The game’s patcher and anti‑cheat fail to initialize when launched through Steam, making Desktop Mode and a Wine frontend (Q4Wine) mandatory.

Once the initial setup is complete, your settings and input configuration persist, but the game must still be launched through Desktop Mode.

Prerequisites

• Steam Deck running SteamOS (current version)
• Desktop Mode access
• Q4Wine installed
• FantaTennis JTFSE game files downloaded from the official JTFSE website

Installation & First‑Time Setup

1. Switch to Desktop Mode

• Hold the Power Button → select Switch to Desktop.
• FantaTennis will not launch through Steam, regardless of Proton version.
• The patcher and anti‑cheat also fail under Steam’s runtime.
• You must launch the game from Desktop Mode every time.

2. Download the Game

• Download the FantaTennis JTFSE installer from the official JTFSE website.
• Extract or place the game folder wherever you prefer on your Steam Deck’s storage.

3. Install Q4Wine

• Open Discover in Desktop Mode.
• Search for Q4Wine and install it.
• Q4Wine will serve as the launcher for both the patcher and the game executable.

Running the Patcher (Mandatory First Step)

4. Launch FT_Launcher.exe via Q4Wine

• Open Q4Wine.
• Add or navigate to the FantaTennis folder.
• Right‑click FT_Launcher.exe → Run.
• Open Advanced Options and set:

Priority = 0  
(This is required for the launcher to behave correctly.)

5. Allow the Patcher to Run

• The launcher will begin downloading and applying patches.
• Let it complete without interruption.

6. Do NOT Start the Game After Patching

• When the patcher finishes, do not click any BAT files or the Start button.
• Starting the game at this stage will cause anti‑cheat issues.

7. Close the Patcher

• Once the folder size increases and all patches are applied, close the launcher.

8. Close Q4Wine Completely

• Ensure all Q4Wine sockets/tickets are cleared.
• Optionally reboot your Steam Deck to guarantee a clean state.

First Actual Game Launch (Required Once)

9. Launch FantaTennis.exe via Q4Wine

• Open Q4Wine again and run FantaTennis.exe directly.

10. Set Virtual Desktop Size

• In the Q4Wine run window, set:

 Virtual Desktop Size = 1920×1080

11. Set Priority

• Under Advanced Options, set:

 Priority = 0

12. Confirm Settings

• Click OK to launch.

13. Wait for Anti‑Cheat Initialization

• The anti‑cheat will patch and install required components.
• This may take a moment; do not interrupt it.

14. Game Launches

• You can now log in.
• Adjust your Settings immediately:
• Configure controls for Steam Deck input instead of keyboard.
• These settings will persist for future sessions.

Regular Use After Initial Setup

15. Using the Launcher Normally

• After the first successful launch, you may return to using FT_Launcher.exe.
• This ensures the game is patched before each session.
• Once patched, you can launch the game normally through the launcher.

16. Anti‑Cheat Stuck?

• If the game hangs on the anti‑cheat screen after launching from the launcher:
• Restart your Steam Deck.
• The anti‑cheat can become stuck and cannot unload itself.

17. Recommended Reliable Startup Method

For a guaranteed clean launch every time:

• Run FT_Launcher.exe first.
• Let it check and apply patches.
• Close the launcher completely.
• Launch FantaTennis.exe directly via Q4Wine (same method as the first launch).

This avoids anti‑cheat lockups and ensures consistent startup success.