Spellthief

Spellthieves are bodyguards, arcane assassins, and mageslayers capable of draining magic and twisting it against their foes. Feared by spellcasters far and wide, spellthieves make mages think twice before presenting their focus.

Steal Spell

3rd-level Spellthief feature

You can siphon spell energy away from your target and wield it yourself. When dealing extra damage with Sneak Attack, you can choose to forgo rolling 2 or more of the d6s to steal a spell from the target of the attack. The level of the spell you steal must be less than or equal to the number of Sneak Attack dice you forgo rolling. Alternatively, you can use an action to touch a willing creature and steal a spell from it without making an attack.

Stealing a Spell. You can only steal spells that a target knows, has prepared, or can cast innately. The target must have remaining spell slots of that level or higher, or have remaing castings of that spell that it has not yet expended. If you have previously seen the target cast a specific spell, you can choose to steal that spell. Otherwise, you steal one spell of the DM’s choice. When you steal a spell, the target expends a spell slot or usage of that spell as if they had cast it at the level you stole, or at the highest level they could cast it at that’s equal to or less than that level. The target can’t cast the stolen spell again until it finishes a long rest, even if it has additional castings of that spell remaining.

If you attempt to use this feature on a creature that can’t cast at least one spell, or that has already expended all its possible castings and spell slots of that level or higher, this feature fails and your Sneak Attack dice are still forgone, but the usage of this feature is not lost. You can use this feature a number of times equal to your proficency bonus. You regain all expended uses when you finish a long rest.

Casting a Stolen Spell. After stealing a spell, you can cast that spell one time without material components that lack a gold cost before finishing a long rest, after which the spell energy fades away harmlessly. Intelligence, Wisdom, or Charisma is your spellcasting ability for these spells when you cast them with this feature (choose when you select this subclass).

Charisma

Your spellcasting ability is Charisma. You use your Charisma whenever a spell refers to your spellcasting ability. In addition, you use your Charisma modifier when setting the saving throw DC for a stolen spell you cast and when making an attack roll with one.

Spell save DC = 8 + your proficiency bonus + your Charisma modifier

Spell attack modifier = your proficiency bonus + your Charisma modifier

Intelligence

Your spellcasting ability is Intelligence. You use your Intelligence whenever a spell refers to your spellcasting ability. In addition, you use your Intelligence modifier when setting the saving throw DC for a stolen spell you cast and when making an attack roll with one.

Spell save DC = 8 + your proficiency bonus + your Intelligence modifier

Spell attack modifier = your proficiency bonus + your Intelligence modifier

Wisdom

Your spellcasting ability is Wisdom. You use your Wisdom whenever a spell refers to your spellcasting ability. In addition, you use your Wisdom modifier when setting the saving throw DC for a stolen spell you cast and when making an attack roll with one.

Spell save DC = 8 + your proficiency bonus + your Wisdom modifier

Spell attack modifier = your proficiency bonus + your Wisdom modifier

Eye for Magic

3rd-level Spellthief feature

As an action, you can open your awareness to the presence of concentrated magic. Until the end of your next turn, you know the location of any spell or magic item within 60 feet of you that isn’t behind total cover. When you sense a spell, you learn which school of magic it belongs to.

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

Mark the Prey

9th-level Spellthief feature

You develop a talent for identifying spellcasters. If you spend at least 1 minute observing or interacting with another creature outside combat, you can determine whether the creature can cast spells, its spellcasting ability, and the highest level of spells that are currently available to steal with your Steal Spell feature.

Spellgrace

13th-level Spellthief feature

Your deep understanding of magic grants you advantage on saving throws against spells and other magical effects and resistance to damage from spells. In addition, when you use your Steal Spell feature, you can immediately cast the spell as part of the same action.

Absorb Spell

17th-level Spellthief feature

You can attempt to absorb spells and harness them against your foes. When you succeed on a saving throw against a spell, you can use your reaction to absorb a portion of the spell, imbuing a weapon of your choice with its raw magical essence. The next time you hit with the weapon within the next minute, the weapon is considered magical and deals an extra 1d6 force damage for each level of the absorbed spell. Once you use this feature, you can’t use it until you finish a short or long rest.