// ==UserScript==
// @name        wikia monobook
// @namespace   wikia-monobook
// @include     *.wikia.com/*
// @description Automatically redirect Wikia pages to Monobook theme
// @version     1
// @grant       none
// @run-at      document-start
// @downloadURL none
// ==/UserScript==

var suffix = 'useskin=monobook';

var url = document.location.href;

if (!url.includes(suffix)) {
  var sep = url.includes('?') ? '&' : '?';
  location.replace(url + sep + suffix);
}