Inspired loosely by The Witcher's Quen Sign, I've created this abjuration spell that's designed to completely negate the damage from a single attack (or similar instantaneous instance of damage like a fall or spell), a whole body shield that dissipates after one use. While concentration is kinda redundant if the spell dissipates immediately after one instance of damage, it's there mostly to as a restraint for higher level casting.
Protective Aura
1st-level abjuration
Casting Time: 1 bonus action
Range: Self
Components: V, S
Duration: Concentration, up to 1 minute
Class: Paladin, Ranger, Sorcerer, Wizard, WarlockA magical aura envelopes the caster's body, protecting it from damage. While the spell is active, if the caster takes any damage from a single instance such as an attack, a fall, or a spell, the caster must make a Constitution saving throw to maintain concentration. On a success, the caster takes no damage; on a failure, the caster takes half damage. Either way, the spell ends.
At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the spell remains active for an additional instance of damage for each slot level above 1st, provided concentration is maintained and the duration hasn't expired.
If I need to be more specific about "Balanced":
- Does this spell's power match it's level or should it be higher?
- Could this spell be easily abused, if so how and what should be added to the discription to prevent such a thing?
- Is it redundant to reiterate concentration and duration at the end of the spell's description?
- And most importantly, Does the spells description make sense, or should the description be re-worded a bit?
Also, while not necessary, if you can think or a more clever name it would be much appreciated.
Best Answer
It's overpowered
As SeriousBri points out in his answer, this ability is pretty much busted for any kind of spell level, but as you've currently worded the spell, it's especially problematic for Wizards and high AC classes like Eldritch Knights and Paladins.
If you're already rocking 20+ AC, most things that will hit you are either crits, or a spell of some sort, which means you're looking at only getting damaged once per turn. This makes the spell rather insane for Eldritch Knights and Paladins, who can simply pop this spell and keep concentration on it until it blocks a crit or a spell, and then recast it if the fight isn't over yet. The fact that it is a bonus action makes this especially troublesome, because it's often not that hard to find time to cast a bonus action, the spell would be a lot less 'must have' if it required a regular action, it prevents stacking Dodge ontop of this spell, making you almost impossible to damage for a turn.
For Wizards, this spell will break the game somewhat at level 18. Most games will never get to that point, but a level 18 wizard can pick a first level spell and basically treat it as a cantrip, casting it whenever you like as long as you have it prepared. I can't think of a single first level spell that I'd take over the ability to block a damage source per turn for a bonus action.
That's not even taking upcasting into account. I've played an Eldritch Knight focused on tanking, and this spell would have basically replaced all the other spells I used.
You're essentially trying to make a less powerful version of Resilient Sphere, so perhaps looking into the restrictions that spell puts on you will make it more manageable. Also changing bonus action to normal action will greatly depower the spell, turning it into a less good-for-every-situation spell.