Launching a Scorpion
The basic method can be performed by two persons (Person A and Person B) working together.
First, set Scorpions as the Primary Heavy Vehicle in Halo 2's multiplayer map Coagulation. Then, have Person A take a Scorpion and drive up the rock near the Shotgun spawn until the Scorpion flips over, forcibly ejecting A from the driver's seat. Person B should use another Scorpion to drive up Person A<I/>'s flipped Scorpion, such that B<I/>'s Scorpion is directly on top of A<I/>'s.
At this point, Person A should flip the bottom Scorpion, launching the top Scorpion into the air. The Scorpion may stay in the air for a surprising amount of time, bouncing off walls, the ground, the invisible ceiling, and sometimes clipping onto the top of the map (provoking Person B<I/>'s death at the hands of the Guardians).
Launching a Player
The process of launching a player is similar to that of launching a Scorpion. Only one player, however, is needed.
The player should flip their Scorpion over near the Shotgun spawn, as described above. They should then stand on top of the Scorpion and flip it.
An Overshield can be used to achieve higher distances. A player with an Overshield can simply stand at the top of the Scorpion, and then run down the treads, flipping the Scorpion at the last second.
On Delta Halo
Tank jumping can also occur, with a bit more work, in Campaign mode. In the level Delta Halo, get the Scorpion to the chapter "You Break It, You Buy It." After killing all the enemies in the area, blow up the energy shield right next to the fountain and drive the tank onto the shield emitter. Sit there until the shield turns on. Move or fire your cannon, and you should go flying around, spinning the whole time. This technique was pioneered in November 2004 and hence filmed by Lleyad.com. This is often far more entertaining—and lethal—than the multiplayer version. This can also be accomplished slightly later on in the level, when you come up on the final outdoor structure. If the trick works, the Scorpion will be flung into the air, often exploding.
Wraith and Scorpion
In any Halo 2 Campaign level with a Wraith and a Scorpion, two players (Person A and Person B) playing Co-op can work to launch the tank. This can also be done in Slayer, if the heavy vehicle settings are set to random on a large map.
Person A should get in the Wraith and Person B should get in the Scorpion. Person A should position their Wraith behind the Scorpion, and boost toward the Scorpion's rear. The boost should send the Scorpion flying into the air.
There is also another neat little trick that will produce almost the same results on the Halo 2 map Zanzibar. First, set the primary heavy vehicle to a Scorpion Tank. During the match, get into the Scorpion and drive it around the windmill. Drive the tank into the windmill, with the front end facing the beach. Keep the tank level as the blade pushes you up the windmill. When the front part of the tank hits the walkway, the tank will start flying through the air.