However, the veteran's guile and wit, their devotion and their motivation, all stem from the meaningfulness of the vow: the veteran cannot deliberately and knowingly use magic, psionics, martial strikes or stances, supernatural abilities, or magic or psionic items. They cannot accept direct magical or psionic aid to their person (Fireballing their foes doesn't count), and must take any save against that aid that is given to them. They are encouraged to shun those who repeatedly give them unwanted aid of this nature, and preferably all magic, but this is not actually required and veterans don't bear any particular enmity towards spellcasters, psionicists or initiators.

A veteran who breaks this vow feels mentally shattered by the transgression, and loses the conviction that fuels veteran abilities (other than class skills, proficiency, and hit dice). These other abilities are regained at a rate of one level per day by adventuring normally as a glorified warrior ("Normally" is subjective, but no attempt should be made to avoid combat beyond the usual measure). For example, an eighth-level veteran who breaks the vow can use a single veteran trick after one day of adventuring, and seven after six days of adventuring. These days don't need to be consecutive. New veteran tricks can be selected in this way, though it would have been faster to relearn them normally!
Martial maneuvers make you lose your class features.