The spell Armor of earth pg. 216 in L5R 2ed Player's guide states:
For the duration of the spell all damage dice rolled against a shugenja which are less than or equal to their caster's school rank are ignored.
So if the caster's school rank is 4, what does that mean?
a) The opponent gets to roll 5 dice and 4 are ignored.
b) Of the dice rolled by the opponent, any value of 4 or lower doesn't affect the caster.
c) Something else completely?