[DF] Holy water seems to have no purpose
 

So far, I haven't found a single DF monster with a Weakness, Revulsion, Vulnerability, or Dread of Holy water, despite its description in the DF 1 equipment list as that being it's only use. Demons and undead in GURPS Magic and GURPS Fantasy are conspicuously missing these traits as well.

So, some questions for the audience:

What classes of monster would you assign these sorts of traits to? All Truely Evil creatures? Undead only, regardless of Evilness? Demons only, same footnote? Different degrees or combinations of traits based on creature type?

I'm thinking of Weaknesses for Undead, and perhaps Revulsion or Dread for demons.

What other uses can you think of for holy water and related substances (holy oils, incense, etc)?
I can see sprinking one "charge" of holy water per hex being good for a +1 to rolls to exorcise a cursed area or reconsecrate a dark altar. If not per hex, then perhaps per yard radius.
It also seems appropriate for area spells of protection - same idea, one bottle per hex.

It's too cheap for Holy characters to use it at a one-bottle per spell benefit unless it's a really trivial benefit - one FP off on the spell makes it 3x the cost of one point of Power Item, but doesn't require a power item of great value to have 20 of them. And the Holy character can get them half price (as per DF2) in town anyways. I would say one per spell, and only on ceremonial castings perhaps.

Any other ideas?

Re: [DF] Holy water seems to have no purpose
 

Holy water should cause damage to demons and undead according to old school dungeon delving.

Re: [DF] Holy water seems to have no purpose
 

Treat it like a powerful acid (1d cor) that only works on demons? The rule say it can be used as a "grenade".

Re: [DF] Holy water seems to have no purpose
 

Indeed; DF7 says as much. That there are no specific effects listed for it (how much damage it does, how long it lasts) is a clear oversight. I'd say that it burns monsters vulnerable to it as though it were acid.

Re: [DF] Holy water seems to have no purpose
 

I know a game in which "faithful" undead take no damage from holy water if it was consecrated by a priest of their faith, which seems an amusing and appropriate rule to me. Never benefits mindless undead.

Re: [DF] Holy water seems to have no purpose
 

Anything that could be repelled by your flavour of True Faith. Basically it's bottled Faith.

Re: [DF] Holy water seems to have no purpose
 

There is no mention of touching a demon or undead with a holy symbol either. Maybe it would do 1 HP damage per level of Holiness or Power Investiture (Holy)? Who knows.

I think the biggest mistake made by the DF series is that the AD&D Dungeon Masters guide was not the starting point. This book is perhaps the most complete book on dungeon delving ever IMO.

Re: [DF] Holy water seems to have no purpose
 

SJG is trying to create a series of campaign style supplements here, not simply trying to mooch off work that has already been done.

I very much hope that SJG continues to make something familiar yet fresh and distinctly GURPSy in the DF line and never tries to make itself into any sort of D&D conversion, clone, copy or anything more derivative than the homage it already is.

That said, I support things that have a Dread of Holy Symbols to count Holy Water as such and if it gets on them they suffer the Agony affliction.

In my campaign...

Demons being the direct adversaries of the gods- Dread and Agony
Devils being the servants of evil gods, but still not demons- Simply Dread
Undead being universally unholy AND directly affected by the symbolic purity of water- Dread and Agony
Elder Things having not much to do with Heaven or Hell-No effect.
Horde Zombies being something other than the usual Undead- No effect.

Anything that is effected by Holy Water at all and is in contact with about a pint of it must roll a d6 every turn till it is dried. On a six they ignite as iff they had clothes on fire as per b434.

Re: [DF] Holy water seems to have no purpose
 

I will say that to me the AD&D DM guide is something that should be copied because it is the standard for all dungeon delving games. This book should have all of its ideas taken and then digested and then fully converted to GURPS rules in such a way that GURPS DF plays like AD&D. The same should be done for the Monster Manual and Unearthed Arcana.

But as far as the holy/unholy stuff goes, there needs to be much more discussion on this topic because good vs. evil is a basic conflict in dungeon delving. The Evil Cleric should also have the same ppowers with unholy water and unholy symbols. The Evil Cleric should have powers to control undead too just like they do in AD&D. IMO of course.

Re: [DF] Holy water seems to have no purpose
 

Well if holy water makes zombies burn, does unholy water make paladins burn? They're like the zombies of team good!

Tasteless joking aside, seriously, what does unholy water hurt that an evil cleric is likely to encounter? It probably hurts angels, but if they're encountering angels, they're probably rethinking their line of work. It probably hurts good gods too, but if they're encountering good gods, they're out of time to rethink their line of work.

You know the saying. "Good Gods!" Yeah, that evil cleric is totally dead. Oh, hm. Maybe I didn't manage to put the tasteless joking aside.