In Lords of the Boards thread I declared I am Enthusiast For Scurvy And Bubonic Plague, so accordingly here are some plans about houserules to make diseases more interesting.
The problem in RAW is that diseases have little storytelling value. One level 3 spell and it all goes away...few DMs even bother with such things because they are just so trivial or have to be some unique bizarre supernatural voodoo disease to which "Remove Disease does not work". Dull, considering how significant things they actually were in medieval times.
So here are some modifications to RAW (PHB and DMG with bit of Spell Compendium thrown in), and couple of new spells to cover midground (and bring fun flavor to that eeeevil villain priest of Nerull). In no way complete but look through. Comments and suggestions are more than welcome.
I'll be suggesting some new diseases and parasites too at some point, oh fun :)
Spells
Delay Disease
Level: Clr 1, Drd 1, Rgr 1
Otherwise like written in Spell Compendium 63
Resist Disease
Abjuration
Level: Clr 2, Drd 2, Rgr 2
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Creature touched
Duration: 2 hours/level
Saving Throw: Fortitude negates (harmless)
Spell Resistance: Yes (harmless)
DC of Fortitude saving throws to prevent infection of disease (DMG 292) is lowered by half of the caster level of the caster. Since supernatural diseases are more susceptible to magical healing, their DC is lowered by caster level of the caster.
Even if the saving throw fails, length of incubation period is doubled.
Heal Disease
Conjuration (Healing)
Level: Clr 3, Drd 3, Rgr 3
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Creature touched
Duration: 24 hours
Saving Throw: Fortitude negates (harmless)
Spell Resistance: Yes (harmless)
DC of Fortitude saving throws to prevent instance of repeated damage and to recover from disease (DMG 292) is lowered by half of the caster level of the caster. Since supernatural diseases (and diseases coming from Contagion spell) are more susceptible to magical healing, their DC is lowered by caster level of the caster.
Even if the saving throw fails, target takes no ability damage during that day.
Enhance Disease
Necromancy (Evil)
Level: Clr 3, Destruction 3, Drd 3, Sor/Wiz 4
Components: V, S
Casting time: 1 standard action
Range: Touch
Target: Living creature touched
Duration: 24 hours
Saving Throw: Fortitude negates
Spell Resistance: Yes
DC of Fortitude saving throws to prevent instance of repeated damage (DMG 292) is raised by half of the caster level of the caster. Since supernatural diseases (and diseases coming from Contagion spell) are more susceptible to magic, their DC is raised by caster level of the caster.
Successful saving throw is not counted for purpose of recovery.
Suppress Symptoms
Necromancy (Evil)
Level: Clr 4, Drd 4
Components: V, S
Casting time: 1 standard action
Range: Touch
Target: Living creature touched
Duration: Special
Saving Throw: Fortitude negates
Spell Resistance: Yes
Suppress symptoms cures all effects of one disease the subject is suffering from. The subject still makes daily Fortitude saving throws to recover from disease but on failed rolls takes no ability damage. The spell stays in effect until the disease is cured, and until then the subject is immune to reinfection by the same disease.
The subject is still carrier of the disease and can infect others. For his own recovery saving throws and infection, ability damage and recovery saving throws of the infected creatures DC of Fortitude save is raised by 5.
Both casting and being willing target of this spell are considered evil acts.
Remove Disease
Conjuration (Healing)
Level: Clr 5, Drd 5
Components: V, S, M
Casting Time: 1 standard action
Range: Touch
Target: Creature touched
Duration: Instantaneous
Saving Throw: Fortitude negates (harmless)
Spell Resistance: Yes (harmless)
Remove disease cures one disease the subject is suffering from. The spell also kills parasites, including green slime and others. Certain special diseases may not be countered by this spell.
Material component: Different for each disease
Contagion
Necromancy (Evil)
Level: Clr 5, Destruction 5, Drd 5, Sor/Wiz 6
Components: V, S, M
Casting time: 1 standard action
Range: Touch
Target: Living creature touched
Duration: Instantaneous
Saving Throw: Fortitude negates
Spell Resistance: Yes
The subject contracts a disease selected from the table below, which strikes immediately (no incubation period). The DC noted is for the subsequent saves (use Contagion's normal save DC for the initial saving throw). Diseases contracted by Contagion spell are considered supernatural for target but if disease spreads to further victims disease is considered natural for them.
(Table in PHB 213)
Material component: Different for each disease
Mass Contagion
Level: Clr 7, Drd 7, Sor/Wiz 8
Otherwise as written in SC 51 (with exceptions to Contagion spell, above).
Modifications to other rules
Destruction domain spells:
3 Blindness/Deafness
5 Contagion
Remove disease ability of paladin is changed to Heal disease ability (similar to the spell with paladin level instead of caster level).
Paladin gets Remove disease ability on levels 10, 14 and 18, but requires material component for using this ability.
Panacea (SC 152) no longer heals disease.
Disease spells and specific faiths
Priests of Nerull (and other sects who are considered applicable by DM) use their holy symbol as material component for both Remove Disease and Contagion. Holy Symbol is not consumed in the spellcasting. However, in most cases casting Remove Disease is considered violation of code of conduct and Suppress Symptoms is preferred.
Druids and priests of Obad-Hai (and other sects who are considered applicable by DM) use their holy symbol as material component for Remove Disease when targetting non-supernatural diseases. Holy Symbol is not consumed in the spellcasting. However, in some cases casting Remove Disease is considered violation of code of conduct (casting Suppress Symptoms is always a violation).
Material components for Remove Disease and Contagion
List of material components in other cases haven't been compiled yet, however most of them should be such that getting them requires bit of work but might also be readily available at least in larger towns, depending on wish of a DM. Piece of brown mold (DMG 76) freshly cut, an amethyst of certain size or heart of owlbear, that sort of thing.