Each profession has its own unique blend of restrictions as a consequence of making the luddite choice. In return for the many and important defences you are automatically and comprehensively afforded as soon as you become a luddite, you are forced to abandon many of the more complex, strategic or new-fangled powers in your profession.
Knights: no interest in crusades or martial motions.
Mages: no elemental roots, no enduring elementalism or elemental preparation.
Loremasters: no interest in the upper skies, heavens or stars; no infection of the rains, no phoenix-rebirth, no use of truesight.
Ranger: no awakening of trees, no bringing forth or interaction with dryads, no interest in totems or ents.
Sorcerer: no interest in shrines thus no Thaumaturgy.
Druid: no interest in dryads, ents or awakened trees.
Thief: no patience for infections, no interest in ballons.
Seer: no connection to the netherworld, no truemystic sapience, no interest in ethereal tempests or oracular materialisation; full efficient bonding for oracles.
As a rough rule of thumb when assessing what you will GAIN from the luddite selection, you can peruse the list of restrictions above and assume none of these abilities will work freely against luddites.
See HELP LUDDITE for details on the luddite concept and selecting it as your chosen mindset.