Decrease their Will saves?

[Brace Cormaeril]

How can I decrease an opponents Will save?

 

[blaggart]

inflict pain is a psion power
mind cloud may -10 off will save
use touch attacks that offer 0 save?

Blaggart

 

[Vuron]

Bestow Curse can be used to give -4 to saves as an effect

You can also go about it in a variety of indirect methods by either attacking wisdom or removing wisdom or save boosting items.

There are some poisons that directly attack wisdom (consequences being will saves are reduced) and touch of Idiocy does damage to intelligence, wisdom, charisma.

Considering many high will saves are the result of wisdom boosting magic items an dispel magic might be useful in temporarily surpressing the benefits to wisdom.

 

[Brace Cormaeril]

Inflict pain is a no-go, as it affects "attack rolls, skill checks ability checks"... poison seem to be a good thing, or is poison use evil?
Thread drift... is poison use evil?

 

[Kurotowa]

If you can inflict the sickened status or any of the fear status effects, it will give them a penalty to all their saves. It's an actual use for Doom!

 

[Vuron]

Poison use isn't an inherently evil act (or it would seem the poison spell and cloudkill would have evil descriptors) but it's definitely seen as "evil" in most cultures. At the least it's largely seen as unlawful.

I'd say it's definitely going to be a major issue in a campaign with Paladins or LG/NG clerics but might not be seen as evil in a game with druids and rangers as poisons are usually made of natural venoms and components.

 

[Victim]

Enervation works especially well since there's no save to resist its effects. Using a Will save effect to reduce someone's Will save is often of dubious value - if you can land the Will reducer, then you could have landed the real attack.

 

[Nefrast]

The coolest and most elegant way is to bring your opponent to voluntarily forego her saving throw and accept the spells result. If you go this cool route he will probably expect a very different spell. Getting the trust of your enemies before you strike is always amusing.
(Technically this is not decreasing the will save but nullifying it completely.)

 

[BlueBlackRed]

IIRC Ray of Stupidity does 1d6 damage each to Int, Wis, & Cha.

 

[shilsen]

IIRC Ray of Stupidity does 1d6 damage each to Int, Wis, & Cha.

Ray of Stupidity does 1d4+1 pts of Int damage. Touch of Idiocy applies a 1d6 penalty to Int, Wis and Cha scores.