One of my favorite tricks is to send my opponent offstage and then gimp them with a reversed Side-B into the stage as they try to recover vertically. The effects are somewhat less potent on stages with walls on the side of the stage (e.g. Green Hill Zone, WarioWare, either of the Yoshi's) since hitting them into the wall gives them the option to tech. Keep in mind that every even-numbered Judge results in some kind of devastating gimping effect.
The procedure goes like this:
1. Verify that your next Side-B is not going to be a 1.
2. Knock the opponent offstage and below ground level.
3. Dash off the edge, putting the opponent between you and the stage.
4. B-Reverse Judge using the momentum from your dash.
5. Whack 'em good.
6. Fastfall and Up-B to sweetspot ledge, hogging if necessary.
7. Profit.
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Here's what could happen:
[9]:
Stage spikes, and then locks opponent into massive hitstun that is only escapable by successfully wall-teching. Not even the best of recoveries can make it back unless they were at really low %, but even then hitstun is still incredibly long. I've never seen anyone escape this on a non-wall stage before. Usually people are too baffled by what just happened to even think about wall-teching, but if your opponent eats a bowl of nails for breakfast every morning (without any milk) then they will just use the big hitlag from the 9 to better react to the wall-tech. On wall stages this result is less effective at low %s if the opponent DI's upwards, since they will fly up into the wall and bounce off at an angle that might let them act before they reach the blastzone. Another possibility is that they smash-DI up so hard that they don't even end up colliding with the wall at all, but this will kill anyone who isn't a fastfaller at moderate %s anyways.
[8]:
Is your opponent Samus? Is it Jigglypuff? Mewtwo? Peach? Zelda? No? Well, they're dead. It doesn't matter what % they're at, they die. No tech nor any amount of furious mashing can save them. The massive chunk of ice engulfing them just plummets straight down into the blastzone. Be mindful of your Up-B when trying to return to the stage though, you might accidentally stall their descent with your hitbox. Outside of that, there's nothing else to do here but reach your hand out to catch the single tear from your opponent's eye. Consume it to assert dominance.
[7]:
This hammer has a lot of the same drawbacks that 9 also has, but is harder to tech and DI because there's barely any hitlag. It's nowhere near as flashy and it wastes a perfectly good apple in the process, but is usually fatal in any case.
[6]:
Hits them under or into the stage, which then spikes them straight down. Not nearly as significant on flat walls, but since it's a semi-spike the bounce will send them somewhat downwards anyway. Fatal in pretty much every scenario but wall-tech.
[5]:
Does not typically kill since it sends upwards, but can still kill on FD, Lylat and Skyworld unless they ceiling tech (let's be real; nobody ceiling techs). You can combo upwards through them afterwards by fastfalling to sweetspot the ledge with Up-B, then drop on them with D-Air since they'll likely be close to your ledge by the time you're ready for them. Meteor smash almost always lands, but in some cases the linger-box can send them upwards diagonally into another stage spike. After that its usually a done deal unless they tech that too, in which case -- who IS this guy?
[4]:
Hitstun isn't very long, but it will send them below the stage at such an angle that they have no options to get back if you hog the ledge. Wall stages bounce them down even further below the stage with some additional hitstun and will usually kill them before they get the chance to act. Either way, ledge hog will confirm.
[3]:
This one is HILARIOUS. This result is the reason why reversing the hammer is important, since this sends your opponent backwards. The knockback isn't that great, but it is really difficult to DI correctly because the angle is never expected. Since it sends them behind you, it launches them horizontally into the blastzone. Even if it doesn't kill them immediately, they're put in a position that nobody could recover from. This hammer result got mega-buffed in 3.5; its damage was nearly quadrupled, it has a base knockback of 20 instead of having none at all, and it now has a knockback growth of 80. On top of this it breaks shields even better now, but that has no real use in this scenario. It's a monster.
[2]:
Another result of 3.5 made this hammer result spike on an air-hit. It's pretty weak, but a spike is a spike. Characters with trash vertical recoveries and fastfallers die from it, and it puts anyone else in a really bad spot. Edgehogging can usually confirm but for characters with a better recovery you can throw some D-Airs into the mix.
[1]:
Nothing exciting outside of the sound effect a successful hit makes. Getting this result isn't necessarily going to kill you since your opponent isn't going to be able to punish you while they're trying to recover, but this is the reason why you rule out this result prior to attempting the gimp. As a rule the odd numbered Judge results are very unreliable, especially for gimping in this manner. On the other hand, the even numbers are reliable for gimping and not much else. The only true use of odd Judges is for combo purposes, and even then you've usually got better options to choose from.
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3.5 made Judge's weakest results much more powerful, and that is what allows this trick to work. Using Judge still remains super risky, but using it as a gimp tool like this takes away most of the risk factors while taking advantage of its incredible power. This is not always going to be the best option every time your opponent is forced to make a vertical recovery, so do not constantly fish for this to work. Other options you have, like D-Air meteor and N-Air stage spike, are almost always going to work just as well and are far more reliable. That said, this is an extremely powerful mixup option that is very flashy and I only recommend trying it in serious play when your opponent is reading your other gimp strategies.
Outside of serious play, do it whenever you please. It's goddamn hilarious.