Joe

The name Joe, in the Id Tech 4 SDK, is the default name for any NPC in Dooom 3. The name "Joe" can only be seen with the NoClip console command. These Joes have no dialogue. An exception is that one of the soldiers in Mars City is named "Ronn", but you can only get to Ronn with the NoClip command as well. The name "Joe" may not mean anything, but it could be a reference to someone who worked on Doom 3, got fired from ID, or died during development. An NPC in Mars Underground, thought to be a Joe, is actually T. Brooks. Another supposed Joe is actually just a static object you can pass through.