Can’t think of many fictional sports besides Genesis in Sket-dance. I don’t particularly like the sport but it was still hilarious
Manga
Yeah I'm kind of having the same problem which made me really interested in the topic, Sketch dance was actually on my read list so knowing they have one is nice.
There is technically Megalobox if we count anime, also JoJo part 7 kind of race which offered complete freedom in vehicle selection and allows for weapons.
I have the feeling that some isekai I read had a sport that demons used to play but I can't pinpoint what it was.
I also remember a doujin that treated sex as a competition as akin to artistic gymnastics
I did try to think of competitions like the death games in Alice in Borderlands, also omniscient readers viewpoint and tower of god had many interedting competitions, but while sports are part of games, games are not all sports, then again, chess is by some considered a sport so I'm currently really confused if any of these games would actually be a sport and where the line lies. Maybe my question should be games in general...
But at the end of the day there just aren't that many games I can remember that I would intuitively consider a sport like it happens for air gear and megalobox. Its kind of disappointing since it is a pretty interesting area to explore for world building and it rarely takes much attention.
The only isekai x sport I can think of is the baseball one. Which is pretty good if u haven’t read that.
I think made-up sports are too hard to do. Even Keijo is really just wrestling with special rules. Made-up board games, on the other hand, seems far more common. They had one in Hunter x Hunter (ant arc), Love is War had a few (thanks to Fujiwara and board game club), and Sket-dance had them. Many gambling mangas also have their own board or card games.
Yeah D frag also made a board game, but my problem with that is that the results feel random as not all rules are explained nor are the squares shown so you only see stuff happen instead of understanding how it would play.
That aside, yeah fictional sports are kind of a difficult concept to pull off (think of how boring quidditch is) and even when they do most are technically variations, but I'm fine with that, if there is a fantasy magic world where they have real sports but with magic I would still consider it a different thing.
I laughed, when I saw it was the 100th chapter I was in disbelief until I saw what the "series" is about, great stuff.
To bad there's no FFX manga. Blitzball is the best fictional sport.