Supernatural Hit Dice

Last September, before I came around to the idea of making public blog posts, there was one which really caught my eye on Necropraxis about the idea of a damage threshold for the supernatural. I loved the concept and thought it would be a great idea to put it into practice. I just needed to wait for the right opportunity to come up. It's been a few months, and I have, so I wanted to throw up the results.

Putting it in Practice

My players had no idea what was going on. They knew that "something" was up when I started asking for their die rolls instead of damage, and when the DM narration started to yield a lot of "useless" attacks. Initial arguments supposed that their attacks weren't hitting. But the dice rolls didn't support that. The next theory, and the most amusing one, was that only every second attack worked. Then a question over the materials used. Then the theory that it absorbed magic.

I had the goal of creating a "hopeless" feeling, and it worked out well: The group ended up fleeing, ironically right on the cusp of success. Explanation's came later, and everyone liked the principle. So we did a bit of fiddling, and I'm posting the end results here, now that time has passed.

Goals

The intention here is to make it possible for a human to harm a supernatural creature without the use of magic weapons. I want it to be damn hard for a normal man, possible for a fighting-man, and doable for a hero. I want a super-hero to not just be able to carve up lesser demons, but to face off against stronger ones. I absolutely don't want a wizard to blow through these with fire-balls - magic should be effective, but the goal should be to dispel, not blast apart.

Implementation

On the PC end:

1. Class based damage die. Fighters inflict 1d8 (1d6 w/small weapons), while other classes inflict 1d6 (or 1d4).
2. Level-based damage bonus for Fighters. This begins as +1 at Hero level, improving to +2 at Myrmidon, +3 at Super-Hero, and then scaling at a reduced rate up to the 19th Level (+6).
3. Magic weapons have no "plus" to damage - Except "Slaying" weapons, which do have a damage bonus, making them damn effective.
4. Fighters of high enough level have an option to learn huge versions of weapons, which inflict 1d10 damage when used by a character of high enough STR.

On the monstrous end:

1. Supernatural creatures possess Supernatural Hit Dice. These are treated as "HD+1" in terms of Attack Throws and Saving Throws.
2. Each SHD has a threshold. The exact amount is determined by the degree of how "magical" the possessor is.
3. The lowest value (6+) is for things like demon possessed humans or the undead; things which have become "magical', but are innately still derived from mortals. They can be hurt by normal men, but only with a good amount of luck.
4. The common value (7+ to 8+) is for various sorts of lesser demons, or other things which are "supernatural, but not exceptionally strange". It is possible for any fighting-man to harm opponents of this sort, with difficulty. Normal men don't have the "oomph" to do it.
5. Powerful supernatural forces, such as name demons, can be hurt only by actual heroes (9+), and put down in good order only by the truly super-heroic. Some could even be stronger (10+) but these would be the top of the top - the Orcus and Demogorgon types, if you will.
6. The absolute most powerful (11+) are creatures on the order of the divine. It is possible for the super-heroic to harm them. You need that much grit, to dare and make a god bleed. I suppose you could also set even higher numbers, but I see no reason to go beyond this point.

This also adds into my "Resistance" mechanic of choice. That is to say: Rather than a monster taking "half damage from fire", the expression is always given based on die. Given the above, it might be noted that at a certain point, most magic-user spells become useless: Even if a fireball does 10d6, if the threshold is set to 7+, you might as well be swinging a torch. Vulnerability is important. If you're battling an Ice Demon, use fire. If you're battling a Fire Demon, think twice? This also helps to replace the long lists of resistances held by demons, devils, and other sorts in most D&D editions - Instead, the more important part is what specific specimens are weak to.

I have to say, I love how it all spins together. Fighting-men are impressive in their own right. Picking out the right tools, and doing your research, is also important: Even a modest dagger, if enchanted with special properties, can give you an edge (if you want to take down a Witch-King, you had best have a barrow-blade). For everything else, there's bashing it until it died.