In Fifth Edition Dungeons & Dragons magic permeates the game in the form of spells, abilities, items, artifacts, enchanted locations, and creatures. It is so pervasive that for many players it exists as an omnipresent force without a moral character; much like gravity, it has a power over their existence in that it affects their physical world but no power over their moral character or choice. Magic simply exists and what we do with it is what matters.
I have never been comfortable with this version of magic in my Dungeons & Dragons games, regardless of the edition I've been playing. Magic has always been something of a double edged sword in my games where magic both gave and took away something from its user. This presented itself most obviously in the items, artifacts, and enchanted locations that I created for my worlds as my players were able to immediately discern the effect and drawback from their use. What's more notable is that it created a sense of dramatic tension for my players when some new magical thing was discovered and made their use an important moment. Potions were examined and fretted over; magical weapons were used with trembling die rolls; and glowing portals were held in awe. It gave the game a dimension that it lacked when the sword was simply given a +2 bonus or the potion announced as a Potion of Healing. It gave meaning to the things my players encountered in the world beyond a statistical bonus or quick fix.
Magic needs this level of tension for it to be meaningful in a role-playing game or else it becomes something ordinary and boring. Look at the way that Cantrips have changed with the D&D 5e. In previous editions theses spells required that the player prepare the spell and think about their use as there were only a limited amount of uses before you had to rest; now, however, the spells can be used at will, without preparation. This isn't necessarily a bad thing, but it makes them less special and their use perfunctory.
So how do we fix this and make magic more meaningful?
I find myself going back to a book I read years ago by Mark A. Garland and Charles G. McGraw, Demon Blade, which had a profound impact on my thinking about magic in fantasy worlds (it's been a few years since I've read the book so forgive me if I explain this poorly). In the book magic draws its energy by consuming the wizard using it. Essentially it consumes the fat and muscle an individual has on their body in order to produce more powerful magics. Little things, like creating a bit of magical light, might make a wizard peckish but the most powerful artifacts and spells could consume them entirely. It made the use of magic something that a person had to think about before doing, and it made magic users even more terrifying as a person who is willing to end their own life to cause you harm is unafraid of anything you could ever do to them.
I like the idea that magic has an effect on the players but I'm not convinced of the best way to accomplish this. I could try having a temporary reduction in constitution in order to cast more powerful spells. This would mean that if a player were to cast 9th level spells that they had to have a constitution score of 10 or better to survive the casting.
It might be double dipping though.
