DC checks are in the 2das, unfortunately. You'd have to edit them to alter the dc checks made when diseases/poisons are applied, though I'm not certain it'd work serverside, not having tested it (though I suspect it will).
Alternatively, if you just want to apply an ADDITIONAL penalty, you can do a second fort save for that, independent of the hardcoded one - is that what you mean? If you just want to tell what poison or disease they have, that is unfortunately not possible in vanilla nwn, so far as I know.
If you're using nwnx_structs, you could almost definitely do this by looking at the effect struct.
Here's an old thread on the subject:
Click MeFunky
Modifié par FunkySwerve, 29 décembre 2010 - 07:52 .