Language Log offers a great post about the comics convention of using typographical symbols to represent swear words.
In any case, !
— * @ # $ % & seem to be the characters most commonly used in the U.S. (I suppose £ and € get some play outside the U.S.) At the moment I have no idea about why = is out of the game.]
I’ve been playing Rogue, so I want to translate that as “potion, scroll, gold, Rogue, corridor, stairway…”