Footstool jump (fsj) is when you press jump in the air while you are on top of a character. You do a jump off their head, if they are in the air they suffer an extremely weak meteor. Like ground jumping fsj can be short hopped and full hopped.
This technique seems useless for edgeguarding, but it’s not. What it does is it allows you to extend extremely far down with any character, edgeguard and still recover. I’ve found this technique to be the most useful with ganon, it lets me do a rising dair and then I still have an airjump and up b to make it to the edge.
Falco’s full fsj is almost as high as sonic’s up-b. I’m sure fsjing will be useful in teams for extended combos, particularly 2v1.
If you fsj a non-blocking/attacking opponent so they go into the stunned animation, some characters can get a guarunteed attack. Like Falcon gets a free Falcon kick(24%!), ZSS, Sheik, Toon Link all get dairs, etc., as long as it’s a move that shoots you downwards. Of course, you have to attack immediately after fsj for it to be guarunteed, which leaves you with relatively little time to see whether your opponent shielded the fsj (in which case they can really punish your attack). But if you have super good reaction times, it can be an extremely safe approach.
it’s used in combos, or the closest thing in this game. also, it disrupts the opponent’s recovery.
you can jump on their heads and ledge-grab for instance.