How does Spell-Eating compare to Energy Drain?

Question

I'd like to replace the standard Energy Drain effect on a few CR3 Wights with the following Spell-Eater effect:

Spell-Eater On a successful Melee attack, the target must make a Will save against a DC equal to 10 + 1/2 the spell-eating creature’s racial HD + the spell-eating creature’s Cha modifier. (Same as Energy Drain). If the target fails the save, one of the following happens:

1. If they cast spells spontaneously: they lose one of their highest remaining spell slots and the spell-eating creature gains 5 temporary hitpoints (lasting 1 hour)

2. If they prepare spells: they lose a randomly selected spell from their highest spell slots and the spell-eating creature gains 5 temporary hitpoints (lasting 1 hour)

3. If they are not a caster, or only have 0th level spells remaining: nothing happens

The goal is to make the creature scarier to casters and less concerning to mundane characters, especially in a campaign where the party can't have a 15 minute adventuring day.

Thus my question is: How does this ability compare to Energy Drain and would it change the CR of a wight? (Bonus question: In general how valuable would this ability be if you were to fold it into the Monster Creation guidelines, so other users could add it to their own monsters?)

Answer 1

Introduction

I would say that this change makes the wights noticeably less of a threat, possibly to the point of making them CR 2 rather than CR 3. There are two questions to consider here...

How Powerful is Energy Drain?

Compare Wights to other CR 3 monsters that are mostly physical threats like Black Bears, Medium Fire Elementals, and Dire Hyenas. Notice how the others have a higher chance to hit and deal more damage when they do. This suggests that Energy Drain is a significant part of a wight's CR rating.

How Powerful is Spell-Eater?

Spell-Eater is certainly not an insignificant ability, but I don't think it compares to Energy Drain. Here are a few reasons:

• It only affects spell casters; Energy Drain affects everyone.
• Losing a high-level spell slot hurts, but a negative level gives you a -1 at almost everything. Even as a caster, I might rather lose one spell than have my caster level reduced across the board.
• Many casters have other options besides casting spells. For example, clerics have channel energy and domain powers, witches have hexes, and wizards have school powers.
• Spell-Eater can't kill anyone, whereas enough negative levels will.
• It's easier to remove - simply resting restores spells (even if you have long adventuring days), whereas negative levels can persist for days.

Also, a wight has a 30 ft. speed and no special movement abilities. A wight isn't that likely to actually get in range to hit a caster. Level 4+ rangers and paladins will be on the front line, but losing a spell shouldn't bother them much. Wights do have high Stealth and an Int high enough to use it effectively, though, so it depends a bit on the circumstances.