800 common Chinese, Korean and Japanese characters
I thought this article might be of interest to people. It is a list of 800 characters that are used all three countries, with shared or very similar meanings. Scholars from all three countries came together and agreed on a set of unifying characters that everyone should learn, they released their findings in 2014. Of course while the languages of all three countries are completely different, their history sharing a writing system ties them together
I think the fascinating property of logographic writing is the way it can allow people with different languages a rudimentary system of communication, almost like a shared sign language. It's a tiny bit like the way math is universal, because all countries share the same way of writing it.
Of course that makes this list very useful for anyone travelling through east Asia as well. It might not be for everyone to learn the 10's of thousands of characters in the dictionary, but 800 is a much more manageable number, and the fact that three countries agreed on them makes it more valuable. Also since the way in which compound words are formed in those three languages is painstakingly logical, you get a lot more out of learning comparatively few characters than you would expect.
The book the article references goes into a lot more detail, and offers a bit of insight into the difference between simplified and traditional characters as well.
(and yes I know Korea mainly uses Hangul day to day , but the country hasn't completely let go of 'Hanja' yet, which I think is nice)
I noticed that in the charts, the Japanese kanji were often slightly different from those from China and Korea. I assume this is because Japan has continued to use traditional Chinese characters and has changed many of them as well.
Also, since most of these are pretty simple and commonly used, just knowing what they mean would be very helpful to anyone travelling in that part of Asia, as you said. Seeing a sign and being able to tell even what half of it says can be a lifesaver in some cases.
It's complicated - Japanese kanji have also been simplified, the forms are called 'Shinjitai 新字体' which was standardised in 1946. Sometimes they use the same method as mainland China, but not always. The changes are not always as drastic as the fully simplified Hanzi, they don't have the brute force approach of replacing anything complicated with 又 or ㄨ, so they sort of sit somewhere in between traditional and simplified sets.
You'll notice that they also the two different Chinese forms in there as well. Where the method is fairly straightforward, eg any instance of the radical '讠' will always correspond 1:1 to traditional '訁' it's quite easy to see the similarities, but even though some of the differences are quite abstract, once you see them side by side, it's hard to 'unsee' them. Eg you can see that eg 圖,图,図 are all variants of a diagram or picture, which is fairly easy to remember.
There isn't really any central single central authority regulating anyone how to write Chinese characters, it's a bit like how every European country that uses the latin alphabet has a different idea of how to do it... The differences are just something unavoidable, because of the different existing standards in use, which is why the tables pragmatically include some variants. It's easier to work with it than try and resist it. It's educational :)
The book is much better at explaining though, I can't find a copy of the English version but heres a nice inside shot of the Korean one: http://generalgraphics.kr/wp-content/uploads/2017/03/808_17.jpg