Are there things similar to chess?

Chinese Chess 象棋

well, the Go should count, this is really fun to play.
Otherwise, did you consider competitive video games? the dynamic is different but surprisingly similar to chess at high level

Maybe it does not have to be a game. Mathematics for example: the Riemann hypothesis, nonlinear differential equations… plenty of room for intellectual effort, maybe more useful than a game.

This Go looks much more strategic, while our chess is very, very concrete. Is this correct? What about complexity and concrete knowledge, compared to chess?
As for Shogi and Chinese Chess my questions are almost the same. Is there a lot of opening theory? Is it as complicated as our chess? Do you end up soon in the corset of wellknown structures or is there more room for trying new things?

@tpr no it doesn't have to be a game, any suggestions are very welcome. As for the mathematics, I think I would have to study many years at university before I would be able to think about some unsolved problems?

You have to study many years before mastering chess or go too. A computer program Alpha Zero got stronger than any human just by playing against itself and with no other input than the rules set. Mathematics study does not need to be at a university, an autodidact like Ramanujan proved that and he even was so poor that he wrote his work on the back of wallpaper as he could not afford to buy paper.

Now I read a bit about this Ramanujan, that was very interesting! But no human can do what Alpha Zero did. My point is not that I wouldn't be ready to study for years to master something. The question is just, how do I spend these years? I don't want to only memorize tons of information. I want to think and analyse on my own. For example some languages are very difficult. But there is not much to analyse, you have to learn tens of thousands of words, connection of words etc. That's boring. Chess is something in between, a lot to analyse, but also a lot to know, you cannot check all these 100.000 opening lines again on your own, you have to trust others and the engine. I would like to find something that is even much more about my own thinking and much less to know.

Magic. Stage magic, I mean.

It may be boring to buy and study the usual cliched tricks that have already been done over and over again.

But you could try to create and invent new illusions and tricks.

That allows for a lot of creativity and intellectual challenge where your imagination and budget are pretty much the only limit.

As in chess you interact with people and try to fool them, to outwit them.

@PhayaNaga
Okay, a completely new and interesting idea here, thank you for this one! I can't say much about it, have to think it over, read about it. And I haven't the budget. But really a creative thought, a new direction to think of, very good!

You can look up "Masked Magician", "Magic Secrets Revealed", "Penn & Teller Fool Us" and similar searches on You Tube to get some basic ideas and to see if you like this kind of stuff. At least it will give you a couple hours of good entertainment.

One of my favourites is "Sacred Riana", for example this video:
www.youtube.com/watch?v=d_etsAX53Ys

And I believe that the best tricks are very simple and cheap to perform. I don't mean stuff like David Copperfield, Derren Brown and Chris Angel do.

A random example is

www.youtube.com/watch?v=mcfIB44Ck8g

but there are so much more impressive illusions out there.

PS: Even if you don't do magic yourself it is fun to watch and try to figure out how the performers did it and if there are alternative ways to do the same illusion.