alternate magic idea for 5e

What if arcane magic was corrosive to the body of the caster? Like smoking cigarettes, or chronic acid reflux?

Casting a spell requires roll + Constitution modifier vs DC 15 + spell level
Success = no Con loss. Failure = reduce Con by an amount equal to the spell level.
Recover Constitution from sleeping or resting.
Rest 2 hours = 1 Con. Sleep 1 hour = 1 Con.
New skill = Meditation (Con-based), after resting for 2 hours roll+Con(+Proficiency) vs DC 20 to recover 2 Con.

Crystal shards from the island of Kapuo are sometimes referred to as Kapuo, or Blueglass, shards.
Blueglass shards are used to power internal forces, as a blueglass shard is used it's essence pours into the caster's body and causes strange effects.
Consuming a Blueglass shard is more powerful, but will solidify the organs over time.

Holding Blueglass during casting gives +5 to casting roll, on a natural 1 the Blueglass fades to a black color is now a worthless, brittle gemstone.
Consuming Blueglass requires Con saving throw.
Failure = Permanently lose 1 Constitution. Success = Permanently lose 1 Hit Point but can cast # of spell levels = Constitution without rolling for Con loss

New Spell: Detect Blueglass
works like Detect Magic but only detects presence of Blueglass

alternately
make Blueglass magical so the wizard has one less spell to cast (by default Blueglass is not magical)


Inflicting pain and bloodletting can power internal forces, and sacrificing life can be the most powerful form of personal enchantment.

Spellcaster can inflict wounds on self to power spells.
If wounding self with weapon they are proficient with, caster can declare how much damage they inflict up to the weapon's normal maximum.
If wounding self with weapon they are not proficient with, caster must roll weapon damage.
Damage inflicted on self = bonus to spellcasting roll
Caster can inflict damage on others with a weapon to get a bonus to spellcasting as long as spell is cast on the next round
(spells that inflict damage do not allow for this same bonus, caster must be the one to inflict damage)
Every 2 hp damage inflicted on others = +1 bonus to spellcasting roll

New Spell: Dedicate Blade
2nd-level spell, cast on any edged weapon, permanent
if the caster uses the blade to kill a creature then the next spell he casts doesn't require a spellcasting roll

LotFP version
all rules same as above, except
Casting a spell requires Spellcasting skill roll, a 1d6 roll. Only arcane spellcaster classes have access to Spellcasting skill.
Skill = level divided by 4 (round down) +1
Wizard level 1 thru 3 have skill of 1, Wizard level 4 thru 7 have skill of 2, etc.
No meditation skill, allow Poison save to recover 2 Con after resting 2 hours
Holding Blueglass gives +1 to skill, rolling 6 causes Blueglass to fade
Consuming Blueglass requires Poison save with same results.
Every 2 hp damage inflicted on self = +1 bonus to spellcasting roll
Every 3 hp damage inflicted on others = +1 bonus to spellcasting roll