diff --git a/src/XIVLauncher.Core/CoreEnvironmentSettings.cs b/src/XIVLauncher.Core/CoreEnvironmentSettings.cs
index 0d067b25..b5975868 100644
--- a/src/XIVLauncher.Core/CoreEnvironmentSettings.cs
+++ b/src/XIVLauncher.Core/CoreEnvironmentSettings.cs
@@ -16,6 +16,7 @@ public static class CoreEnvironmentSettings
     public static bool ClearAll => CheckEnvBool("XL_CLEAR_ALL");
     public static bool? UseSteam => CheckEnvBoolOrNull("XL_USE_STEAM"); // Fix for Steam Deck users who lock themselves out
     public static bool IsSteamCompatTool => CheckEnvBool("XL_SCT");
+    public static uint AltAppID => GetAltAppId(System.Environment.GetEnvironmentVariable("XL_APPID"));
 
     private static bool CheckEnvBool(string key)
     {
@@ -39,6 +40,14 @@ public static string GetCleanEnvironmentVariable(string envvar, string badstring
         return string.Join(separator, Array.FindAll<string>(dirty.Split(separator, StringSplitOptions.RemoveEmptyEntries), s => !s.Contains(badstring)));
     }
 
+    public static uint GetAltAppId(string? appid)
+    {
+        uint.TryParse(appid, out var result);
+        
+        // Will return 0 if appid is invalid (or zero).
+        return result;
+    }
+
     public static string GetCType()
     {
         if (System.OperatingSystem.IsWindows())
diff --git a/src/XIVLauncher.Core/Program.cs b/src/XIVLauncher.Core/Program.cs
index b37dabaa..6a169c2a 100644
--- a/src/XIVLauncher.Core/Program.cs
+++ b/src/XIVLauncher.Core/Program.cs
@@ -196,7 +196,15 @@ private static void Main(string[] args)
 
         uint appId, altId;
         string appName, altName;
-        if (Config.IsFt == true)
+        // AppId of 0 is invalid (though still a valid uint)
+        if (CoreEnvironmentSettings.AltAppID > 0)
+        {
+            appId = CoreEnvironmentSettings.AltAppID;
+            altId = STEAM_APP_ID_FT;
+            appName = $"Override AppId={appId.ToString()}";
+            altName = "FFXIV Free Trial";
+        }
+        else if (Config.IsFt == true)
         {
             appId = STEAM_APP_ID_FT;
             altId = STEAM_APP_ID;