Overgeeked mentioned: DM fiat is not universal, Just what exactly your DM does at their table does not truly matter to what my DM at my desk does. Until It really is codified in the rules, it doesn't make any difference. Your runecasting potential is Intelligence, and spells or spell-like https://rpginfontips.com/dnd-caster-how-to-maximize-your-spellcasting-power/