Within the speedrunning scene of Luigi’s Mansion 3, we have several skips in the game that involve Gooigi pushing Luigi into places he normally should not be in. These are all under the blanket term “Gooigi Pushing.”
Gooigi Pushing is not a strat that you can do whenever you want. It requires some pre-run preparations. Notably, it requires a “Seed” to successfully pull off.
The “Seed” is a numerical value inside the game’s code. This value as far as we can tell alters the physics engine of the game. This value is a random number that is generated every time the game is booted up from the main menu of the Switch and cannot be forced manually. Certain values allow you to do the Gooigi Pushing strats, while others do not. The ones that do are called the “Seed.”
In order to get the seed, you must shut your game down and reboot it, then test it at the Gooigi Tutorial at the start of the game by trying to push Luigi out of the gate with Gooigi. This is the safest and fastest strat to test the Seed as it is impossible without a good seed, while some other strats may not need a good seed. To do this, have Luigi at the far-right corner of the gate, facing south-west, with him either sucking or blowing with the vacuum. Then, have Gooigi spawn and face Luigi, and be a little south-west away from him. Then flash Luigi with the strobulb and run Gooigi into him diagonally. If you have the seed, Luigi will slide out of the gate. If you do not, Luigi will stay in the gate and you have to reboot the game again to try again.
Here is a video clip example of that happening:
The process for finding the seed is 100% random and can take anywhere from 5 minutes to 2 hours. However, once you have the seed, you will keep it forever until the game is shut down. Switching profiles, switching files, going to the menu, putting your switch in sleep mode, will NOT make you lose the seed. Only by the game fully shutting down/crashing will you lose the seed.
Side note: There is also a chance that upon booting up save files after obtaining the seed that the game will refuse to let you enter the Virtual Boo pause menu. Should this happen, the only way to fix it is to walk back into E.Gadd's Lab manually. At which point the game will allow you to pause again as normal.
