Warding an Area against Undead

[Maat Mons]

Is there a way to prevent undead from entering an area, or deal ongoing damage to undead creatures in an area?

Forbiddance deals damage once when entering, but then undead who don't die outright can chill inside for as long as they like. Also, if a Lawful Good caster casts Forbiddance, it might wind up accidentally murdering various Lawful Neutral and Neutral Good people who happen to pass by.

Antipathy is mind-affecting, so undead are immune. Even if it did work, creatures that make the saving throw can enter, and chill out in the area for as long as they want afterward.

Consecrate gives undead some penalties, but that just makes them slightly less efficient at murdering the people in the area, which they can still enter without difficulty.

Hallow gives some defensive bonuses, but that just puts it in the same boat as Consecrate.

Is there a way?

[Venger]

Does the spell itself need to be anti-undead, or does a generic spell which you can give simple commands to fit the bill? How big of an area do you need protected and for how long? If it's indefinite, perhaps a resetting trap might suit your needs.

[Maat Mons]

If a spell gives you freedom to designate who's affected instead of being locked into undead, so much the better.

Indefinite duration preferred. Barring that, the longer the better.

If it needs to be recast periodically, then definitely no xp or gp cost. Even if it lasts forever, it would still be preferable to have no xp or gp cost.

For area, the bigger the better. But if it lasts indefinitely and doesn't cost gp or xp, it would be fine to spam a small spell many times to cover a large area.

[liquidformat]

If you are ok with a slight homebrew Antilife Shell (http://www.d20srd.org/srd/spells/antilifeShell.htm) that blocks out only undead seems reasonable within the confines of making spells. Also making a version of that spell that only effects undead might be grounds to reduce it to level 5.

I am actually surprised that there isn't a spell that prevents undead from entering an area. For example that seems right up Hallow'ed alley...

[Zaq]

Celestial brilliance is a moderately ridiculous 4th level spell from BoED that lasts days/level, is portable (it's cast on an object and follows the object), and deals 1d6 damage/round to undead in its radius with no save and no SR. An undead critter who's trapped within that range and doesn't have enough fast healing to overcome 1d6/round is eventually toast unless they can get out or negate it somehow.

Repulsion is self-targeted, has a short duration, and isn't restricted to undead-only, but it's not mind-affecting, so it does indeed stop undead who fail their saves.

[Jack_Simth]

Celestial brilliance is a moderately ridiculous 4th level spell from BoED that lasts days/level, is portable (it's cast on an object and follows the object), and deals 1d6 damage/round to undead in its radius with no save and no SR. An undead critter who's trapped within that range and doesn't have enough fast healing to overcome 1d6/round is eventually toast unless they can get out or negate it somehow.

At 4th, there's also room for Maximize (and Empower as well). A flat 6 points of damage per round will overwhelm even a vampire's fast healing 5 (and if you empower it too. that's an extra 1.5 damage per round on average).

[RexDart]

Not the most potent or longest-lasting solution, but the alchemical Gravebane (in the Arms & Equipment Guide) prevents undead from crossing a square filled with its smoke for one minute. Unless they can make a DC 10 Will save, that is....

(Has anyone ever made rules for enhancing the potency of alchemical substances with magic? Gravebane, for example, would be somewhat useful with a higher DC, greater range or duration, etc.)

[Palanan]

Pathfinder has Symbol of Healing (https://www.d20pfsrd.com/magic/all-spells/s/symbol-of-healing/), which can be used to cover a choke point to deal positive energy damage as they pass through. Might be useful for a layered defense.

[SangoProduction]

Is there a way to prevent undead from entering an area, or deal ongoing damage to undead creatures in an area?

Forbiddance deals damage once when entering, but then undead who don't die outright can chill inside for as long as they like. Also, if a Lawful Good caster casts Forbiddance, it might wind up accidentally murdering various Lawful Neutral and Neutral Good people who happen to pass by.

Antipathy is mind-affecting, so undead are immune. Even if it did work, creatures that make the saving throw can enter, and chill out in the area for as long as they want afterward.

Consecrate gives undead some penalties, but that just makes them slightly less efficient at murdering the people in the area, which they can still enter without difficulty.

Hallow gives some defensive bonuses, but that just puts it in the same boat as Consecrate.

Is there a way?

Fluff wise, Consecrate and Hallow should be very repulsive to an undead. And should ward those that aren't determined or directly commanded to move through. The equivalent of Shaken or Sicken condition, when cast on an altar, which are similarly not pleasant conditions to have.