How to Mod Sonic Adventure on Steam Deck

This classic of the platformer genre has been very close to many gamers' hearts and particularly so to the die-hard community that calls the Steam Deck home. Customization alone has compelled quite a few people to delve into modding. The complexity of installing mods on a Steam Deck has always scared many users off.

This guide will simply demystify the process with clearly stated, concise instructions on how to enhance your Sonic Adventure experience. In this rich resource, any old modder or even someone new to game customization can be assured of knowledge and tools necessary to install favorite Sonic Adventure mods for playing.

By the end of this guide, you'll be well-versed in the steps, troubleshooting common issues, and looking to optimize your mod setup for the best performance on the Steam Deck. Let's take off on this modding journey!

How to Mod Sonic Adventure on Steam Deck?

Sonic Adventure modding does appear somewhat daunting, but the truth is that it's relatively easy compared to most games. First off, you want to run Sonic Adventure DX once. This creates some essential game files needed for modding. For the best results, be sure to install the game on your Deck's internal storage.

Now that you have done these, switch to desktop mode. You will need to open your Steam library, right-clicking on Sonic Adventure DX and selecting "Properties," then clicking on the "General" tab. From here, find the "Launch Options," then click on "Configure." In the box, paste this without quotations: "WINEDLLOVERRIDES="d3d8=n,b" %command%." This is a very important command for mods requiring D3D8.

First, enable compatibility with Sonic Adventure (SAADX). Right-click the game in your library, select Properties, open the field with Compatibility, and enable the option "Force the use of a specific Steam Play compatibility tool." Now select "Proton Experimental" from the dropdown. Start SADX once to finish this part.

Next, install Protontricks from the Discover store. This tool is going to help run the mod installer. Download SADX Mod Installer and find the resulting "sadx_setup.exe." Right-click it and select "Open with" and then select "Protontricks Launcher." Now, use the Protontricks window to select SADX and continue.

Start up the SADX Mod Installer. On the setup screen, it'll want the install directory of the game. By default, it's "Z:\\home\\deck.steam\\steam\\steamapps\\common\\Sonic Adventure DX." Once installed, run SADX.

You should now be greeted with the new launcher, which allows you to access your Mod Manager. You will now be asked to download and install .NET 7 in case you don't have it installed. Open the .NET 7 installer by using Protontricks like before.

After installing .NET 7, open SADX again and then open the Mod Manager. Go to the Manager Config tab to set up the Game Directory. Paste the path mentioned earlier or use the folder icon to find the location where Sonic Adventure DX was installed. Save.

Now, to finally access downloaded mods, use the Mods section inside the game's interface. Finally, to get the best audio possible, enable "Use BASS" in the Game Config settings before launching SADX. Additionally, to fit better on the Steam Deck, go into the Graphics settings and change the resolution to 1280x800.

For external mods, you can search on GameBanana. Once downloaded, add your desired mods into the "mods" folder in the SADX installation directory to integrate them into the gameplay.

By doing so and making necessary precautions, you should now be good to go for a modded Sonic Adventure on your Steam Deck.