3 ways:
-Amulet of free action makes you immune to paralysis. They're fairly uncommon, though.
-If your PV is above about 15, you should be immune to death by ghuls and mimics. Strong paralysing monsters (master mimics, hiveminds, etc.) need a PV of about 30 or higher (and decent DV) to be relatively safe. Having fairly high (>150 or so) HP normally is enough to avoid ghul/mimic deaths as well even if your PV is a bit lower.
-Sipping a pool will occasionally give you paralysis resistance.
Hoping to win with every class, doomed. Archer, Barbarian, Bard, Beastfighter, Druid, Elementalist, Farmer, Fighter, Monk, and ULE Priest down.