main.json

{
  "action": {
    "name": "if",
    "params": [
      { "name": "gamefile.exists", "file": "gamefilesd" }, "==", true,
      "and",
      { "name": "gamefile.exists", "file": "gamefileshf" }, "==", true,
      "and",
      { "name": "gamefile.exists", "file": "DIABDAT.MPQ" }, "==", true,
      "and",
      { "name": "gamefile.exists", "file": "hellfire.mpq" }, "==", true,
      "and",
      { "name": "gamefile.exists", "file": "hfmonk.mpq" }, "==", true
    ],
    "then": { "name": "game.load", "file": "gamefileshf" },
    "else": {
      "name": "if",
      "params": [
        { "name": "gamefile.exists", "file": "gamefilesd" }, "==", true,
        "and",
        { "name": "gamefile.exists", "file": "DIABDAT.MPQ" }, "==", true
      ],
      "then": { "name": "game.load", "file": "gamefilesd" },
      "else": {
        "name": "if",
        "params": [
          { "name": "gamefile.exists", "file": "gamefilesd" }, "==", true,
          "and",
          { "name": "gamefile.exists", "file": "gamefilesflare" }, "==", true,
          "and",
          { "name": "gamefile.exists", "file": "fantasycore" }, "==", true
        ],
        "then": { "name": "game.load", "file": "gamefilesflare" },
        "else": { "name": "game.load", "file": "gamefilesd" }
      }
    }
  }
}