Partner Cube Glitch
Overview
Example of player stuck in cube
Partner Cube Glitch (also known as Cube Glitch, Cube Cheat or Super Jump) is a physic engine glitch in multiplayer which allows your partner to accumulate vertical velocity and it also triggers Player Physics Deformation. It is not useful in Challenge Mode, nor in AMC due to the slow setup needed, however the majority of the cooperative least portal maps require it.
Gaining velocity
If your partner is standing still, walk toward him while holding the cube, and drop it at his feet. If you did it at the right timing, the cube should move towards the center of your partner hitbox, and he shouldn't be able to move.
To give vertical velocity to your partner, push the cube on the X axis, (±90). He will be pushed upward while being stuck in the cube so he will accumulate velocity. Landing on your partner will give you upward velocity. You can also grab the cube, but your partner will be given the velocity he accumulated.
If the one in the cube is Blue, it is recommended to use cl_showpos 1. He will see the velocity grow as you push the cube. Anything below 600 UPS is pretty much useless. However if the one in the cube is Orange, velocity will seemingly stay at 5 UPS, but the glitch still works the same way, as the game simply fails to update velocity in cl_showpos hud correctly.
After a certain threshold (around 900 UPS) the one stuck in the cube can press a directional key right before grabbing the cube and you will get velocity both upward and towards the direction pressed.
It is recommended to not look at the cube for any of the player to avoid autograb.
Using a ball
When using a ball it is harder to gain velocity as the spherical shape of the ball will make it leave the player more easily. However there are two known ways of doing it, both requiring a corner.
First way, the player being stuck can go against the corner, while the other stuck the ball in him, while keeping w pressed. To prevent the ball from escaping, and giving velocity, the player pushing the ball will need to hold w and spam a/d. As soon as the required velocity is reached, the ball needs to be grabbed to release all the velocity.
Second way, the player being stuck go a bit off the corner, so ball can be stuck between him and the corner. Velocity will grow slowly, but the ball will never fly away. To release all the velocity, just grab the ball. It's the slowest and most random way to do it, as you can be ejected sideway.
Player Physics Deformation
By doing a cube glitch, you will give to the player stuck Player Physics Deformation. His hitbox will start to rotate. That's why it is recommended to crouch after each attempt to reset it, and making it easier to get the glitch again. It is possible to Cube Glitch yourself when your hitbox is tilted by walking towards the -x direction and dropping the cube in front of you.
If you have disabled gravity because of Crouch Flying Glitch, you can also make your hitbox spin (see spinning hitbox in PPD).