Diagrammatic Pieces define the pieces moves on the item itself. This removes the need to memorize the moveset to the symbol needed in many forms of chess
Western Chess - Maple Landmark
Wooden Pieces with the moves written on the bottom (so you have to lift them up to see)
Maple Landmark Image
Japanese Chess - Dobutsu Shogi (in the greenwood)
https://en.wikipedia.org/wiki/D%C5%8Dbutsu_sh%C5%8Dgi
Cute animals with the moves indicated by dots around the edge of the piece, probably the best diagrammatic set I've seen
Dobutsu shogi image
Japanese Chess - Kumon Study Shogi set
Very similiar to dobutsu shogi, but with the original character written in the middle instead of a cute animal. The wood feels good in the hand
Study Shogi image
Eastern chess sets will often have "westernized" pieces, that are different non-language characters symbols, but still require people to memorize a symbol lookup table.
I'd love to find diagrammatic options for Chinese Chess (XongQi), but I haven't seen any - do you know of options?
Oh, I don't need this to help children! I need this so I don't forget the moves myself, and to get other adults to enjoy a game or two.
Having a 30 something learn 15 something symbols to play a game or two to see what it is like is a big ask.
https://en.wikipedia.org/wiki/List_of_chess_variants
There are many different types of chess out there, and as a game tourist I want to make things easy on myself. Chu Shogi has 21 different symbols for example, it's going to take a minute to memorize that, and good luck convincing someone else to memorize it to play a few games.
example:
chu-shogi without diagrammatic pieces vs with