The runes that are placed on the runic stones tend to be very individual based using many different languages developed over the long history of earth. This may mean that someone who is say English has to use Egyptian symbols to get the effect wanted as it was found that symbols seem to have the best effect as more complicated langue tend to hold several different meanings for one word.
Even though there are only so many effects that runic stones can have/do some can we put together to make a different effect , like having fire and water stones make steam. Some combinations only work for certain individual’s as it depends on their human nature/power level/and if they have studied the aspects of that runic field as again not having a grasp on it will take more power than most have available.
Even though the creation of shaped Runic stones is very individual based any soul user can use another person’s stone but this does not apply to memory based stones as those do require the memory tied to it.
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