Mr. Greenwood, why in Realms does magic not work ‘on the fly’? Why can’t spellcasters create spontaneous effects according to their needs? Similar to ArsMagica/Mage Ascension. I imagine to fit D&D, but what is the explanation…inRealms? Spellcasters must have tried.

— Ed Greenwood (@TheEdVerse) August 1, 2020

1)
Hi, Rodrigo. Some Realms spellcasters CAN work magic ‘on the fly’…all Weavemasters (such as the Chosen of Mystra, including Elminster), for example, and many who have the Gift (innate ability to wield the Art), but who don’t…2)
…use arcane magic (wizards, sorcerers) or divine magic (clerics). There are many forms and systems of magic active in the Realms, but D&D tends to concentrate on arcane and divine magic, for player characters.#Realmslore

— Ed Greenwood (@TheEdVerse) August 1, 2020

3)
By all means run your own game campaign with characters using other systems of magic, but you’ll have to work out, or adapt, other rules systems to run the magic. Whatever works for you!#Realmslore

— Ed Greenwood (@TheEdVerse) August 1, 2020