|What the FUCK, yugioh, that's awesome! Where is THIS show?|
Everything I can think of that does Level Drain is either some unspeakable abomination, some crazy weird eldritch trinket or trap, or something along those lines. People hate Level Drain because it can be hard to recover from without shlepping back to town and paying a bunch of money. Not every party cleric is going to roll something capable of helping you. You are determining your spells randomly, right?
And I get it. Putting your cool stuff from next level further away is a bummer. Taking away toys you thought you already earned can feel disappointing. The loss of HP involved could be deadly. In the past I have usually made Level Drain work more like XP debt, something extra you have to clear or be cured of before being able to advance. That's not a fix in fiction, though.
Cort the Druid doesn't head back to the tavern going "Ah hell, I got Level Drained." Or even "That spirit raked its claws upon me and I did feel my essence weaken; it will be long before I am what once I was, longer still before I am up to the challenge of the Hazeon Hex." That second example sounds fine in fiction except for focusing on the energy lost. That kind of thing, from a monster's perspective, puts focus on energy GAINED and opens us up to a boring Ecology Of post that describes all these hoary horrors in knowable, safe terms. How does the Friggit use the energy it takes from level drain? Does it sustain it? If so how often does it need to feed? What happens when it doesn't? If it just gets more powerful from level drain why isn't that reflected in a called-out monster level-up mechanic?
That kind of thing makes for an interesting episode of Planet Earth but I don't want someone interested in my nightmare creature. I want them to go OH SHIT.
Level Drain should be about the Oh Shit experience from the character's perspective. Not just fear - running away from the dragon is a pragmatic solution and failing a morale check or a save vs. a Fear spell is no different really than being outclassed by a level 36 wizard's Lock. You're just dealing with a bigger number at that point. Not just the player's anxiety about losing toys. This is something primal, superseding normal mental or physical reactions and mucking about in your soul. Your spirit, your kung fu, is reduced by these interactions. They are less about taking from you and more about shaking you. Creating cracks in your foundation, cracks you might fall into.
Lovecraft's dedicated authors and those of his imitators largely don't have to worry about death-by-octomonkey. A lot of them die from 1200 CCs of sheer crazy.
That's what I think we're talking about with, say, a wight. It's not there to claw you open or suck you dry like Shang Tsung. It's there to stop your heart in terror, cosmic force-of-the-universe terror, and if your body fails from your mind and soul falling away like ashes in a rainstorm then that aperture in creation is what makes your old wormbait start walking around under its own power again, as something outside of nature drives you like a car. It's not enough to leave you a shell of your former self. Nature abhors vacuum. An empty shell must be filled.
I think a lot of monsters are defined by how they can kill you, how many attacks doing how much damage and such. I think it's a pure way to think about a monster in a childlike, fairy tale, folklore, Pearce Shea, wendigo, Dracula, demoniac, Roswell sense to think about how a monster can GET you. I think this is why Slenderman caught on. Honestly it's probably a lot of how Freddy caught on: most movie killers have to chase or trap you, while Mr. K only had to exist. The child murder and rape and stuff was barely necessary except to justify how upstanding lawman John Saxon could ever commit a crime. Those of us more familiar with his filmography know that he's actually committed lots.
That was a big digression but my point is, I hope, clear. We have whole games built around sanity mechanics. We have lots of people trying to adapt those and bolt those on to D&D in some way. We've also got this mechanic for ghoulish apparitions that nobody likes to use. Seems to me an economic sort of rehab would be just folding the new spice into the existing batter.
So, Level Drain:
Level Drain works like it says on the tin. You lose one of your HD worth of HP. If you're one of these fancy classes with d12 for a hit die then sorry bro, you're subtracting 1d12. That's your chi being fucked with by this experience. A lot of those classes with huge hit dice are things like barbarians which, yeah, them having a worse reaction to the unnatural works in the fiction. In this way, though, you can actually survive being LD'd down to Level 0/Normal Human, as long as you are lucky with your HP loss. The only thing I don't love is that this is usually a to-hit roll instead of a save. Making it a save would let you deal more in Presence, so more in atmosphere. The to-hit roll works for Game of Thrones, though, so I'll leave it there. That's easy enough to mod on the fly.
That XP loss though...where does that go?
Every time you suffer the effects of Level Drain you gain what I normally would refer to as "1 point of Shock" or something. Today I'm saying you gain 1 level in Being a Crazy Boy. That XP you lost? It goes here, but there aren't hard XP thresholds. It's abstracted as a level of psycho-spiritual wounds.
A common fix for LD in many campaigns is letting Remove Curse fix it. In that case, this is also a good way to have on-the-fly Curse/Remove effects, damaging your willpower patchwork. Also fun and fast for those crazy monsters later on who drain multiple levels at a time.
When you gain enough XP to level up you may EITHER advance to your new level as normal OR "spend" that XP to remove a Crazy Boy level. Actually, this setup works even if you never reduce the target's XP, it just gets a different KIND of experience from its contact with the weird.
Crazy Boys are:
-X to all saves, where X is their Crazy Boy level.
-X to all healing, where X is their Crazy Boy level.
+X to damage with melee weapons, where X is CBL.
+X to the difficulty of saves against your spells (or +X to your Turn Undead result)
After your first CBL you are +1 to defense/save/whatever vs creatures with Level Drain.
When you have CBL 4 you gain your level as a bonus to morale checks vs the supernatural, attempts to understand madmen, and attempts to interpret the primordial tongues from beyond.
When you have CBL 8 you can no longer sleep and are never surprised.
You can see how some people, especially murderous or power-hungry ones, might allow themselves to gain levels in Crazy Boy. This isn't just good for Sanity effects, this can act as a kind of moral damage.
Characters reaching CBL 9, what would normally be Name Level in another traditional class, basically become monsters. They haven't been consumed and filled by the Outside. They have been changed by it, embraced it, and are now something perhaps no mightier than a man but much much different from one. The DM controls your character now and no amount of house rules and Remove Curse will save you. You're an other thing now. This, by the way, is how Moon Slave finds both his generals and the gristly body offal which greases the spindles of new wars.
Sum up: I can use Level Drain to close off parts of the existing game as written. I think it wouldn't take much, though, to open its victims up to a whole new game inside the one they're already playing.