Relog Teleportation

Relog teleportation is a multiplayer glitch that moves a player upward out of collisions when they disconnect and reconnect.

How it works

Disconnecting saves the player's position. Reconnecting restores it, then checks the player's full collision box. An overlapping player moves upward in one-block steps. X and Z stay unchanged.

The check uses block and entity collision shapes, not visible block outlines or suffocation. Any positive overlap counts. Touching a collision face exactly does not.

The lift stops at the first collision-free position it tests, not necessarily the surface. The player's box is 0.6 blocks wide and 1.8 blocks high. A two-block-high cavity can stop an ascent underground. A one-block-high gap cannot contain the whole body.

Water and lava have no collision box. The lift can stop with the player submerged in either fluid, provided no other collision shape overlaps the player's box.

Wall-contact rounding

The glitch can occur while the player stands in air on a cave floor beside a wall. Burial and suffocation are not required.

Movement shifts the edges of the client's collision box separately. The reported horizontal position is the centre of that box. The server rebuilds a fixed-width box around that position. Floating-point rounding can make the server's box extend slightly into a wall even when the client's box ends exactly at its face.

Ordinary server movement checks a box inset by 1/16 of a block on every face. A rounding overlap fits within that margin. Login checks the full box without the margin and starts the upward correction.

Wall contact does not always leave an overlap. Different approach positions can produce exact contact, a tiny gap or a tiny overlap. Only the overlap starts the lift. There is no fixed success probability or random chance in the login correction.

Singleplayer

Saving and reopening a singleplayer world does not apply this login correction. The saved player position is restored without the server's upward collision check.