Void warp is a family of glitches which allows you to spawn into an area with room and x,y,z coordinates set in a different map by manipulating a variable known as the Zoneout Type (located at 8011B934 in NTSC 1.0) to change after the "Next Base Entrance Index" variable has already been copied over to become your new "Base Entrance Index". This technique was formerly considered a form of wrong warping, and was banned in No WW, No IM/WW, and Glitchless, but with the current understanding of void warp the two glitches are classified separately.
By using a number of the different tricks below, we are able to change the Zoneout Type variable after the "Base Entrance Index" (8011A5D0) is set.
The Zoneout Type variable is used to determine how Link left the previous scene, in order to set up certain properties when spawning into a new scene. The following is a list of values that this variable will be set to, and what each value represents:
When spawning in a new scene, having the Zoneout Type set to 1 through 3 will restore a saved room and x,y,z coordinate, as well as a rotation value. The data for this is starts at 8011B938 (NTSC 1.0) with type 1, with each record being 0x1C bytes long. By changing this value so late on exiting a scene, we are able to restore a set of coordinates we would otherwise not be able to.
The game loads the scene and map that the timer normally brings Link to, but at the coordinates of his entrance point in the previous scene.
Using cutscene diving or Remote Control Epona, Link can use FW over a void. If Link warps away with FW just as he voids out, he will void warp. The game loads the scene in which the Farore's Wind point is set, but at the coordinates and map of his entrance point in the previous scene.
This will take you to the coordinates at which Farore's Wind was set but the scene which the loading zone takes you to. If Farore's Wind is set in a map which has a map number higher than any maps in the scene to which the loading zone takes Link, the game will crash. This can be done using RCE Epona, Slope Dives into the loading zone, or by pressing FW while still in fade-in (eg: from Forest, Spirit, or Shadow cutscene skips)
The game successfully loads the next cutscene, but Link appears at the coordinates of the Farore's Wind point previously set.
The game sends Link to the scene and map it normally does, but at the coordinates of the Farore's Wind point previously set.
Using Ocarina Diving or RCE, Link can play the Ocarina in mid-air over a void. This can lead to some interesting effects, including the ability to void warp with warp songs. This is impossible in most spots, as Link must be very high up in the air in order to have enough time for the song and the warp cutscene to play out. It will bring Link to the map and scene the warp song normally brings him to, but at the coordinates of his last entrance point in the previous scene.
Currently this is only possible during the Ganon's Castle collapse sequence, and is used in the fastest Any% route to skip traveling down most of the Castle during the collapse.
Performing a Farore's Wind or Ocarina dive into a void in Death Mountain Trail or Ice Cavern will not result in a void warp, due to the Zoneout Type variable being set to -1 (Warp back to initial spawn), instead of 1.