Now a days many of the game data has written something in unknown language like- 爅 Ai0 �区鞞
拽)�4pT曁啪@m� how to encode this

Answer 1

you mean decode.
open game code and find the part that encodes this and try to reverse it.
most people nowadays only want to edit specific values thus use hexadecimal/binary editors, if you dont want to do reverse-engineering/decompiling then you should get a hex/bin editor and detect where the value(s) you wanna edit is.
note that this is hacking and might get you in jail.

Answer 2

what is game code and reverse engineering??