3 if the series has something going for it like an author I like (but not love) or is a canon part of an IP. Likely only 1 if I have no outside reasons or context for the manga or HATE the pilot. We are talking about a "bad" product after all. 3 chapters can easily total 100 pages/half a volume. Even with weekly series due to 40-page pilots and nearly 30-page followups before the page rate goes down to about 18 pages in week 3. That´s enough.

Edit: Astro Royale´s is 101 pages long + a pin-up after chapter 3 to prove my point. It´s mediocre and not bad but 100 pages are more than enough in such cases too. Glow-ups can happen but such cases market themselves and if I know that something sucks before getting good, Star Trek TNG took over 2 seasons to get good, then I might march through it.

I've answered 11-20, but the real answer is a lot higher. I've given hundreds of chapters before for novels I wanted to be good but just weren't (Overgeared), novels that eventually became good (ISSTH) and manga that I kept pushing and pushing through but it simply wasn't for me (Jojo's Bizzare Adventure).

I asked this on reddit several years ago: https://www.reddit.com/r/manga/comments/pw58th/seven_chapters_rule/
My answer didn't change: 7 chapters.

I don't really have a single solid answer, it just varies too much. This poll made me curious so I wasted too much time putting all the numbers of the series from my "Dropped" list into a mean, median, and mode calculator, and the results are
Mean: 15.744186046512
Median: 10
Mode: 1
With the highest chapter I dropped a series at being 122

Sometimes if a series is off to a bad start or something really grinds my gears about it I can drop it after reading the very first chapter (I NEVER drop anything mid-chapter, I just can't, no matter how much I hate it I have to finish whatever chapter I'm on), but if the description/cover seem particularly intriguing, it seems like there might be more to the story and it could actually be really good, or if I've seen a lot of people talking about how good it is, then I'm much more likely to persevere.

Occasionally I'll find a series has a pretty bad or a slow start, but the rest of it is actually really good, so it was worth hanging on there, but that kind of thinking also tends to make me keep reading series that I don't like at all. Other times I'll just be curious to find out what happens next or how things will turn out for a particular character even if overall I don't like the series at all and think it sucks, and that'll keep me reading even though I'm not enjoying it, or I end up hate reading hoping to see a particular character suffer or fail. And sometimes I just keep reading for no reason at all even though I'm not enjoying it just because I'm already reading it and it's hard to make the firm decision to call it quits.

I've gotten so overwhelmed these days with all the series I'm trying to follow that I have improved at dropping stuff I don't like though, particularly if it's predictable and cliche. I can only take so many emotionally constipated black haired dukes of the north forming an unhealthy and yet somehow still boring and predictable obsession with a noblewoman who's actually a reincarnated or transmigrated Korean woman because he finds her "interesting". If the romance is going to be that rinse and repeat then it needs a story and a main character that are compelling enough to make up for it, otherwise it's not worth the read.

Well, it depends..

When it comes to manga, I can take it 4-5, or even 10, if it piqued my curiosity. But for manhwa I'll leave after 1-3 chapters if I'm not interested.

It really depends - if I started the series on a whim, I won't even finish the first chapter if it's bad. If there's a small aspect of it that I like I might give it three chapters, and if I've heard good things about it I can hold out for ten chapters or even just read the whole series, even if I think it's trash. I think the art is the dealbreaker for me. When a series has terrible art I can't bear to read it no matter how well written.

It depends of the genre, but usually 3 or 4 chapters.
Anime around 4 eps. I can see if I'll like it or not.

It depends on how bad the start is.

There will be manga where I read 1 chapter, go "what. why would I want to see what happens next." and then drop it.

But on average, if I thought it looked interesting enough to even open, I will give it 10 chapters to get interesting. That's usually when I decide to drop the few Jump manga I find truly boring.

The trouble comes when an interesting manga becomes boring... unless it has become an actual painful slog to read I will finish it out. Like Bleach from Hueco Mundo onwards....

Sort of depends on how bad it really is. I said 4-5 because I usually give it the first volume.

3-ish. If ch. 1 isn't good, I usually skim the next one or two to see if it gets better.

Usually 3 or so, but the first chapter needs to have at least something that keeps me reading past the first chapter if it's bad, whether that be the art style, character design, setting, etc.

I can't fathom how little you guys value your own time if you are willing to give the series more than 1 chapter to unfuck itself.

6-10 usually, though often after i read 3-5 and it is still meh i would skip to like middle or end of first season to see if it intrigues me (at that point i already don't care about spoiling myself the series), but overall would usually end up reading more than 5 that way...

If the story does something I find really egregious in the beginning then I just drop it immediately. But, if the art is really pretty then I’ll usually skim through a couple more chapters hoping the story u-turns and the plot point gets resolved quickly

Depends on how badly it starts off. If it has my hardline nos: rape, toture with gore, exceedingly bad art, cliche plot, stupid characters, child mc/regression to babyhood then if i see enough hype about it and i dont have more than 20 series i am following on a weekly basis then sure, i will try it again.

Of course that isn't weighed the same for those nos - i will read something with a child mc if they age up before the end of season 1. I will read something with bad art if it has a good plot/good cast. I will read rape/torture if its not romanticized or not the main plot of the story or the mc (female and otherwise) doesnt go back to the one who did that and is actively trying to overcome the trauma of it.

TLDR: Depends.

Depends on my mood as with it. If there's a series that's below par or repetitive I might just continue reading it until I get up to date if that's just my mood that day. Doesn't really mean I'll ever get back to it tho, I've read plenty of manga/manhwa with 50+ chapters and never read them again. If it's real bad though then I'd read maybe 1 chapter.

I don’t drop manga that often (I have 29 dropped manga on this website, but the number of manga I’ve read all the way through is way higher), but when I do, I tend to drop it after only one or two chapters. Of course, there are exceptions, but the furthest I’ve ever gotten into a manga before dropping it is six chapters.

Usually 6-10 but I have read some until 20-30s hoping it will get better before. Usually good art keeps me going for a bit longer. If it's bad plot + subpar art it would be 5 chapters at max.

Used to finish everything, but I think I'll drop it relatively early nowadays mmm...

I'll give a series one volume to catch my interest. (so roughly 5-8 chapters)
If it has no redeeming qualities by that point, I'll drop it.
If I'm still not sure, or there's something keeping me interested (good art, intriguing storyline, etc.) then I'll continue on for at least a few more volumes.

If I'm still not really feeling it that much after three volumes, I'll usually drop it at that point (which I suppose is typically around the 15-25 chapter mark).