Until a day ago, that is. Known GTA V modder Guadmaz has released the most user friendly single player mission creator mod, with an extremely wide range of features. This is a very early release, but it is already an extremely versatile tool. As of yet you cannot create custom cutscenes (this will work with the Rockstar Editor, we assume), and the waypoint system has yet to be implemented, but the mod is getting frequent updates, with the current build being 0.2a.

One of the advantages this mod has over the Creator is that this allows you to load up building interiors which can be accessed while playing the mission. In the Creator, the interiors can only be accessed when building, but in actual play they are off limits.

The mod also allows for you to make use of other modded content, which, the official Creator, obviously does not. This feature basically makes the list of possibilities endless, and it removes more or less all limitations to your creativity.

The mod works with the Rage Plugin Hook, one of the main cornerstones of GTA V modding, so if you've been using mods already, chances are you already have it downloaded.

Coupled with the Map Editor, once the cutscene creation function is implemented, this mod will allow you to craft your own campaigns, and share them with other GTA V players. What kind of mission ideas do you have for GTA V?