What causes people to lose their jumps?

[Miryafa]

Everyone knows Kirby loses his jumps (except for 1) after up-B, and sometimes you hit jump but get hit so quickly it looks like you didn't get a jump. Or you might be offstage, recovering, and get hit off again before you can touch the ground. I also recently learned you lose your 2nd jump when you get hit out of up-B. So I'm not asking about those.

I want to know about the other times you don't get a second jump. The other day I deliberately avoided using a second jump in order to recover with it later, but after I got hit back I wasn't able to second jump at all. Another time I jumped once, got smashed off-stage, and didn't have a 2nd jump to recover with.

Being surprised by not having a 2nd jump usually loses me a stock when I could have recovered, so it's pretty frustrating. Can someone please help me understand this?

 

[Keman]

Do you play with Tap jump on or off? Maybe you're accidentally jumping and not noticing it? As far as I know there is no random mechanic in the game like that where you lose a jump without using it (besides what you mentioned). What character is this happening on for you.

Sometimes when stuff like that happens its easier for us to just blame the game and fault it instead of looking at something maybe we our self did wrong. Only direct answer to that problem I can give you is "Practice more", but maybe there is some strange reason that I have never heard of or had happen to me that I'm unaware of.

 

[Miryafa]

Thanks for replying. To answer your questions:
-Tap jump on
-Possibly I'm jumping without realizing it, but I have a hard time believing that, because some of the times it's happened I only jumped once and then immediately got hit, or (iirc) didn't jump at all
-I don't think there's anything random either, and that's only more reason why I want to know what is going on.
-Every character (the example I gave was with Fox though)

I'm really asking for explanations, not advice. When you don't know, please don't say "practice more," unless you specifically meant "if you practice more, I'm sure at some point you'll figure out what it is." In that case, I'm posting here because I'd rather hear from someone who knows the answer, since I've been playing for 2 years now, and if that isn't enough practice to know what's going on with a game, I'm not sure I can put in the amount required.

 

[Vashimus]

It varies from character to character. Some characters use up their jumps after certain specials, others have special techniques that use up their jumps when used (hovers and glides), some regain their double jumps after doing a special, etc. What you should do is familiarize yourself with your character's recovery options are and what moves leave them helpless when done in the air.

Outside of those character-specific situations, if you find yourself without your double jump, then it's entirely your fault. You didn't "lose" your jump, you either used it carelessly and got hit out of it or used a move that put you into a helpless state beforehand. Learn to conserve your double jump and only use it when you need to or when you know it can't be punished. Sniping double jumps is a thing, and players will do it if you let them.