Digging

Introduction
Jumping on the head of the spade entity will warp the player forward (depending on spade orientation), often enough to clip through walls. Additionally, "Digging" may refer to the spade entity being the easiest entity to pull through walls outside the map.

Performing the glitch (Spade Jump)

 * 1) Position the space close to, but not touching the wall that needs to be breached. Have the spade orientated so that it is parrellel to the wall.
 * 2) *The positioning of the shovel will be different depending on the wallset used in the level, so some trial and error will may be required when testing this glitch.
 * 3) *If the spade pushes you away from the wall when jumping on it, rotate the spade 180 degrees so that it faces the other direction.
 * 4) Jump straight into the wall, landing on the centre of the head of the spade and continue moving forwards.
 * 5) *This glitch can be quite random and wall specific and may take a few attempts, even after practice.
 * 6) *Running and walking make the glitch behave differently and may work better or worse in some cases - trial and error testing with this is recommended for each application of the glitch in your run.
 * 7)  You will be pushed into or through the wall

Performing the glitch (Spade through the wall / Tunnelling)

 * 1) Stand next to the wall (Perfereably from outside the map) and grab the spade towards the middle or handle end.
 * 2) Move the spade away from the player's body (mouse wheel up in Amnesia: The Dark Descent and justine)
 * 3) Rotate the spade so that in the following step the spade will be parrallel with the wall/floor/ceiling/door during the collision. Rotating the spade so that the head impacts the wall first can also work well on corners.
 * 4) Turn as fast as possible, the spade should "Tunnel" through the wall

Note that this glitch only seems to work on certain wall sets and has not seen much testing.

Shovel glitches explained
The tendancy of the spade to "glitch out" and punt the player through the wall and into objects is a result of a combination of properties in the entity. Firstly, the shovel entity has a rather complex collision body, especially by the head of the spade. Secondly, the shovel has the "Can Attach Character" property enabled - this means if the player is standing on the shovel, and the shovel moves, the player will move too (Think standing on a carousel - you move with the carousel and don't stand still while the floor rotates underfoot). Finally, the shovel can be pushed and moved by the player body ( "Collides Character" & "Pushed by Player Gravity").

As a result of these properties a chain re-action occurs. When the player stands onto the shovel head, the shovel is moved by the player - often in a slightly erratic way due to it's low mass and stange shape. The shovel will then move the player because of the "Attach Character" property, however, as the player has moved the shovel will collide with the player again (this is made very likely by the shape), causing a feedback loop.

Eventually, forces will have built up enough in the shovel so the player is pushed enough to leave the shovel head completely.

Tunnelling seems to be only a property of the shovel's shape and certain wall sets - the fact that the spade is incredibly thin when parrallel to the wall/ceiling/floor seems to make it easier to pull out the map. The complex shape around the spade head may also help by confusing the collision response slightly too.

Known objects with similar properties

 * Barrels (Specifically the very edge of the barrel) - See also Barrel Spin Boost.
 * The Bucket item in the cells - This is like a far more volatile barrel and spade combination.